The question presented in this appeal is whether a district court can conditionally enforce an Internal Revenue Service (IRS) summons to ensure that the IRS will not violate the nondisclosure of return information provisions contained in 26 U.S.C. § 6103 while it conducts a tax investigation. We answer this question in the negative.
*1343I.
The facts giving rise to the present controversy, as set forth in the panel opinion on rehearing in United States v. Barrett, 804 F.2d 1376 (5th Cir.1986) {Barrett II), are as follows:
[Dr. Bernard M. Barrett, Jr.] is the president of an incorporated medical practice specializing in plastic and reconstructive surgery. In 1979 the IRS began an audit of Barrett’s personal and corporate income tax returns for the years 1976, 1977, and 1978. When the initial investigation uncovered a $100,000 discrepancy between Barrett’s books and his bank records, the IRS transferred the case from its civil to its criminal division.
Agent Michael O. Hanson, to whom the case was transferred, determined that it would be necessary to inquire of Barrett’s patients the amount each had payed for Barrett’s services. To this end, Agent Hanson sent two sets of summonses calling for patient’s records, one to the hospitals where Barrett practiced and one to Barrett himself. All but four of the hospitals complied with the summonses providing a total of 350 patients’ names. [Barrett has also complied with the summons.] Agent Hanson then sent a letter to each patient advising that Barrett was being investigated by the Criminal Investigation Division of the IRS and requesting documentation of fees paid to Barrett.
Barrett II, 804 F.2d at 1377.1
In United States v. Texas Heart Institute, 755 F.2d 469 (5th Cir.1985), the district court refused to enforce the summonses issued to the hospitals. A panel of this court reversed that decision and remanded the case to the district court for a determination of whether the mailing of the letters to Barrett’s patients would be a violation of 26 U.S.C. § 6103, and, if so, whether enforcement should be conditioned upon requiring the IRS to desist from further unlawful disclosures. 755 F.2d at 482.
In the initial panel opinion in this case, United States v. Barrett, 787 F.2d 958 (5th Cir.1986) {Barrett I), this court upheld the district court’s decision to enforce unconditionally the summons issued to Dr. Barrett. The court also limited the scope of Texas Heart, refusing to hold that a violation of section 6103 was grounds to deny enforcement of, or to conditionally enforce, the summons. Judge Brown dissented, arguing that the court had implicitly overruled Texas Heart. Dr. Barrett subsequently filed a petition for rehearing. The court responded by withdrawing its earlier opinion, affirming the enforcement of the summons, but also remanding the case to the district court for it to follow Texas Heart and inquire whether section 6103 was being violated; if so, then the court was to conditionally enforce the summons to prevent the IRS from making disclosures in violation of section 6103. The government petitioned for a rehearing of that decision. This court granted the request, agreeing to rehear the case en banc.
In this appeal the government contends that the holding in Texas Heart that a district court has the authority to enter conditional summons enforcement orders to prevent a violation of section 6103 should be overruled. The government also contends that the district court’s order unconditionally enforcing the summons in this case is correct and should be affirmed. Barrett responds that district courts hearing an IRS summons enforcement proceeding have long been held to have the power to modify a summons to prevent a violation of law by IRS officials or to protect the rights of a taxpayer. Thus, it is argued that district courts should be allowed to consider section 6103 in deciding whether to conditionally enforce the summons.2 *1344Therefore, we must examine the validity of the rule established in Texas Heart that in a summons enforcement proceeding a district court can consider whether a section 6103 violation may occur, and, if it does so find, determine whether to conditionally enforce the 'summons. The first issue we must address is whether the case before us is moot. Before we examine that issue, however, we briefly discuss the relevant background necessary to decide the mootness issue.
II.
This case involves the construction of a number of Internal Revenue Code (the Code) provisions. First, section 6103(a)3 establishes a general rule that tax returns and tax return information are confidential and may not be disclosed by officers and employees of the United States.4 If a government official violates the nondisclosure provisions of section 6103(a), he is subject to criminal prosecution under section 7213(a)(1). This section makes it unlawful to disclose any return or return information except as authorized by the Code. A willful violation is punishable by a fine of up to $5,000, or imprisonment of up to a period of 5 years, or both. 26 U.S.C. § 7213(a)(1). Moreover, if return information is impermissibly disclosed, section 7431 provides the aggrieved person with a civil remedy. The person can bring a cause of action against the United States, and can recover damages of a minimum amount of $1,000 for each unauthorized disclosure. Id. § 7431(c).
The other relevant provisions of the Code are those relating to the IRS’s power to seek information relevant to a tax investigation. The IRS is authorized by section 7602(a) to issue a summons to compel any person having possession of books of account, papers, or other data to produce such materials when needed by the IRS to determine the correctness of a tax return or otherwise to determine the tax liability of an individual. If the person does not comply with the summons, the IRS can file a petition for enforcement with the district court. 26 U.S.C. § 7604.
In United States v. Powell, 379 U.S. 48, 85 S.Ct. 248, 13 L.Ed.2d 112 (1964), the Supreme Court set forth four criteria that the IRS must establish in order to have a summons enforced:
(1) The IRS agent must show that the investigation will be conducted pursuant to a legitimate purpose;
(2) that the inquiry may be relevant to the purpose;
(3) that the information sought is not already within the IRS’s possession; and
(4) that the administrative steps required by the Code have been followed.
Powell, 379 U.S. at 57-58, 85 S.Ct. at 255. The Court also instructed that a court could inquire into the underlying reasons for the examination and that it should not *1345permit its process to be abused. Id. at 58, 85 S.Ct. at 255. “Such an abuse would take place if the summons had been issued for an improper purpose, such as to harass the taxpayer or to put pressure on him to settle a collateral dispute, or for any other purpose reflecting on the good faith of the particular investigation.” Id.
The government bears the initial burden of proving that the four Powell requirements have been satisfied. Texas Heart, 755 F.2d at 474. Once the government makes the required Powell showing, the burden then shifts to the party resisting the summons to challenge the summons on any appropriate ground. Powell, 379 U.S. at 58, 85 S.Ct. at 255 (quoting Reisman v. Caplin, 375 U.S. 440, 449, 84 S.Ct. 508, 513, 11 L.Ed.2d 459 (1964)). These grounds include that the IRS has failed to meet one of the four Powell requirements, or that the enforcement of the summons would abuse the court’s process.
III.
Before we reach the merits in this appeal, we must address the preliminary issue of whether the case before us is moot. Although neither party has raised the mootness issue, this court is required to do so sua sponte, because this issue implicates the article III requirement that there be a live case or controversy.5 Donovan v. Air Transport District Lodge No. 146, 754 F.2d 621, 624 (5th Cir.1985). The mootness concern is based upon the fact that Dr. Barrett ultimately complied with the summons after he was unable to obtain a stay of the district court’s summons enforcement order. This court has often held that an appeal from an order enforcing a summons becomes moot once the taxpayer complies with the summons. See United States v. Sherlock, 756 F.2d 1145, 1146 (5th Cir.1985); United States v. Sweet, 655 F.2d 54, 55 (5th Cir.1981); United States v. First American Bank, 649 F.2d 288, 289 (5th Cir.1981); United States v. First State Bank of Clute, 626 F.2d 1227, 1227 (5th Cir.1980), cert. denied, 452 U.S. 908, 101 S.Ct. 3037, 69 L.Ed.2d 410 (1981); United States v. Carpenter, 425 F.2d 264, 264-65 (5th Cir.1970); Baldridge v. United States, 406 F.2d 526, 527 (5th Cir.1969); Grathwohl v. United States, 401 F.2d 166, 167 (5th Cir.1968); Lawhon v. United States, 390 F.2d 663, 663 (5th Cir.1968).
Thus, in Sherlock we held that since Sherlock complied with the summons, his appeal was moot. Sherlock’s argument that the government continued to benefit from the material did not persuade the court otherwise. 756 F.2d at 1146. In First American Bank this court also held that compliance with a summary enforcement order mooted an appeal from that order. The appellants argued that the issues were not moot because, if their contentions that the district court erred in determining that the summonses had a valid civil investigative purpose and that the IRS agent violated the automatic stay provision of Fed.R.Civ.P. 62(a) were correct, the IRS could not use the documents so obtained in any future civil or criminal proceeding. The court disagreed, stating that, “The possibility that evidence must be suppressed in a future proceeding, however, is not enough to prevent mootness in this case.” 649 F.2d at 289. In Carpenter this court, without elaboration, held that the appeal of a summons enforcement order that had been complied with was moot. 425 F.2d at 265. Likewise, in Baldridge the appellants had complied with the summons, so the court held the case to be moot. The court also disagreed that a question of substantial public interest should allow the case to prevent its mootness, or again that the court should hear the appeal to determine whether the records would be admissible in a subsequent criminal or civil trial. 406 F.2d at 527. In Grathwohl this court stated that since the appellant had appeared and complied with the summons, there was no relief that she could obtain on appeal and the case was moot. 401 F.2d at 167. Finally, in Lawhon we held that there were no *1346issues to decide because the records and books that were the subject of the order to produce had been produced. Thus, the court dismissed the appeal for mootness. 390 F.2d at 663. On motion for reconsideration, the court stated, in what has become an often quoted passage:
This motion, in effect, seeks to have this court give an advisory opinion as to the admissibility in evidence of the records or their product in the event of a subsequent criminal trial. Such event may not occur. This court passes no judgment on the question whether, if the mooted records are used in a subsequent prosecution of the taxpayers, if there be one, their introduction would be forbidden as violating the constitutional rights of the defendants.
Id. at 663.
Although none of the above authority provide much analysis, apparently the common denominator in each is that once an individual complies with a summons enforcement order, that person is precluded from appealing any issues that attack the validity of the district court’s decision to enforce the summons. Even an attack on the enforcement of a summons based on the fact that information obtained by the summons may be used improperly in a subsequent civil or criminal proceeding is not enough to prevent the case from being moot.
Many other circuits have also held that compliance with an IRS summons moots an appeal of the validity of the summons enforcement order.6 The basis for these decisions, whether implicit or explicit, is the proposition that “federal courts are without power to decide questions that cannot affect the rights of litigants in [the] case before them.” North Carolina v. Rice, 404 U.S. 244, 246, 92 S.Ct. 402, 404, 30 L.Ed.2d 413 (1971). Thus, once an individual complies with a summons enforcement order and produces the documents, a successful challenge to the enforcement order could afford no relief; the information has already been provided and thus this court would be powerless to provide relief that would affect the rights of the litigants.
Based on this precedent, the government contends that since the IRS has been supplied with all the information it sought pursuant to the summons, the case should be dismissed as moot. In determining whether this controversy is moot, it is necessary to keep in mind the single issue that has been presented to the court: whether a district court can conditionally enforce a summons in order to prevent the government from violating section 6103.
To decide whether this issue can survive a mootness challenge, it is helpful to first examine both the holding in Texas Heart that forms the basis of the government’s contention and our opinion in Barrett II. In Texas Heart this court was faced with the issue of whether the district court correctly declined to enforce summonses issued to four hospitals. We reviewed the issue under the four part test established in Powell. The portions of Texas Heart relevant to this appeal are the court’s analysis of the “legitimate purpose” prong of the Powell test and the “abuse of process” inquiry that a court should also make.
The court in Texas Heart found that the IRS did have a legitimate purpose, 755 F.2d at 479, but then addressed Dr. Barrett’s contentions that the IRS lacked a legitimate purpose because of alleged violations *1347of section 6103. Id. The court pointed out that an improper disclosure of section 6103 information was relevant only to the extent that it would demonstrate either an abuse of process or a lack of legitimate purpose, id., but concluded that if there were any improper disclosures, they did not demonstrate either bad faith or an improper purpose. Id. The court went on to note, however, that:
This Court does not hold that unlawful disclosures of returns or return information by the IRS can never be sufficient evidence of lack of a legitimate purpose for the investigation such that IRS summonses should not be enforced. Rather, this Court holds that in this case, even accepting as true that improper disclosures occurred, any alleged improper disclosures do not rise to the level necessary to demonstrate bad faith in the issuance of the summonses or lack of a legitimate purpose for the investigation.
Id. at 481 (emphasis in original). Even though the improper disclosures did not reflect a sufficient degree of bad faith or lack of legitimate purpose to deny enforcement of the summons in their entirety, the court held that the district court nevertheless could require the IRS to abide by section 6103 before it would order enforcement of the summonses. Id.
Thus, this language allows a summoned individual to raise the issue of a section 6103 violation to attempt to defeat the enforcement of the summons. If a violation does not rise to a sufficient level to defeat the enforcement of the summons, though, it nevertheless can still cause the enforcement of the summons to be conditioned. This remedy forms part of the basis of the government’s contention that Texas Heart incorrectly established that a district court can conditionally enforce a summons.
The government’s objection to Texas Heart is also based on the court’s discussion dealing with the abuse of process inquiry a court must make. While the court found no abuse of process to such a degree that it would be necessary to deny enforcement of the summons, the court did note that it still could be an abuse of process to allow enforcement of summonses when the IRS conceded that it would continue to disclose information in violation of section 6103. Id. at 482. The court did not point out in that discussion, however, whether a violation of section 6103 would be sufficient to completely deny enforcement of the summons. From the prior discussion relating to “legitimacy of purpose,” however, it appears that enforcement could be completely denied if an abuse of process was established. See id. at 479, 481. Nevertheless, the court clearly held that if an abuse of process were found, the district court would have the discretion to condition enforcement of the summonses by requiring that the IRS agree to desist from further violations of section 6103. Id. at 482. The court in Texas Heart then established the inquiry the district court would be required to make prior to conditioning the enforcement of the summons:
(1) determine whether the described information falls under the definition of returns or return information in section 6103, and
(2) if so, the district court must further determine whether the IRS is authorized to disclose the information under section 6103(k)(6).
Id. at 482.
The court stated in Barrett II that in Barrett I it misgauged the scope of the holding in Texas Heart. See Barrett II, 804 F.2d at 1377. The concern, however, was not with whether the summons was properly enforced by the district court.7 Rather, the single issue resolved by the opinion in Barrett II was whether a summons could be conditionally enforced:
[W]e find that our mandate in Texas Heart requires the district court to consider whether enforcement of the IRS summons should be conditioned in order to protect Barrett against unnecessary disclosure of the fact that he is under *1348criminal investigation. We affirm the order of the district court enforcing the IRS summons; we remand for the district court to determine whether the summons should be conditionally enforced.
Id. at 1379. In compliance with Texas Heart, the opinion in Barrett II decided to remand the case, not for the purpose of having the district court delve into the propriety of enforcement, but instead to determine whether the district court should condition the enforcement of the summons to protect Dr. Barrett from a violation of section 6103. We have consistently treated the issues of (1) whether the enforcement order was properly rendered and (2) whether an enforcement order can be conditionally enforced as distinct issues on appeal.
With this same distinction in mind we now consider whether the issue in this appeal is moot. Barrett II would have remanded the case to the district court for it to determine whether the summons should be conditionally enforced based on Texas Heart. See Barrett II, 804 F.2d at 1379. Since Dr. Barrett has complied with the summons, Judge Rubin’s dissent argues that the enforcement proceeding is over and we can consider no aspects of that proceeding, including whether Texas Heart requires that the summons should be conditionally enforced. However, we do not agree that such a result is mandated. We recognize that in Texas Heart the enforcement order had not been complied with by the four hospitals, and, in fact, the district court had refused to enforce the summonses, so the controversy was still alive in all respects. But, the court reversed the district court and ordered that the summonses be enforced. Even though the enforcement issue had been decided, the court still held that the district court retained the authority to determine whether section 6103 was being violated, and, if so, to condition enforcement to avoid the violation. Thus, that same issue that we held was alive and must be considered by the district court in Texas Heart is likewise the sole justiciable issue in the present case.
Moreover, the conditional enforcement issue does not attack the validity of the district court’s order to enforce the summons. Thus cases such as Sherlock do not control here. Those cases prevent a party from appealing the validity of an enforcement order after the party had complied with the enforcement order by having furnished the IRS with the sought after material. The issue here does not address the validity of the enforcement order. Instead, it addresses whether the district court after a decision to enforce a summons can attach conditions on the government’s use of the information obtained under the summons. The district court in Barrett II did not decide whether there was a violation of section 6103, and, if so, whether to condition enforcement of the summons on the government’s compliance with that section. If we were to hold that Texas Heart was correct and the district court should have made such an inquiry, we could then provide relief to Dr. Barrett by remanding the case to the district court for such consideration. We point out that the IRS has not yet contacted Dr. Barrett’s patients and section 6103 information has not yet been disclosed.8 Thus, if we were to remand this cause to the district court, it could prevent the IRS from violating this section. This is the relief Dr. Barrett desires.
Accordingly, we conclude that the conditional enforcement issue presented in this appeal is not moot, and we, therefore, decide whether a district court can conditionally enforce a summons order so as to prevent violations of section 6103.9
*1349IV.
We begin by noting two important considerations in summons enforcement proceedings. First, we point out that these proceedings are intended to be summary in nature. The sole purpose of the enforcement proceedings is to ensure that the IRS has issued the summons for a proper purpose and in good faith. See Powell, 379 U.S. at 57-58, 85 S.Ct. at 255. Also, this is only an investigative stage; no guilt or liability on the part of the taxpayer is established. The enforcement proceeding should be concluded expeditiously so that the actual investigation can be continued with the goal of reaching the final determination of whether there will be any civil or criminal liability for the taxpayer.
We also recognize that the Supreme Court has consistently declined to circumscribe the breadth of the summons authority that Congress intended to grant the IRS, “ ‘absent unambiguous directions from Congress.’ ” United States v. Arthur Young & Co., 465 U.S. 805, 816, 104 S.Ct. 1495, 1502, 79 L.Ed.2d 826 (1984) (quoting United States v. Bisceglia, 420 U.S. 141, 150, 95 S.Ct. 915, 921, 43 L.Ed.2d 88 (1975)); United States v. Euge, 444 U.S. 707, 715, 100 S.Ct. 874, 880, 63 L.Ed.2d 141 (1980). For example, in Powell the Supreme Court refused to read into section 7605(b), which prohibits “unnecessary examination[s],” a requirement that enforcements of summonses be founded on probable cause. The Court reasoned that “[although a more stringent interpretation is possible ... we reject such an interpretation because it might seriously hamper the Commissioner in carrying out investigations he thinks warranted_” 379 U.S. at 53-54, 85 S.Ct. at 253, quoted in Euge, 444 U.S. at 715, 100 S.Ct. at 880.
Similarly, in Donaldson v. United States, 400 U.S. 517, 91 S.Ct. 534, 27 L.Ed. 2d 580 (1971), the Court declined to limit the summons authority to cases where no criminal prosecution was contemplated. “Any other holding,” said the Court, “would thwart and defeat the appropriate investigatory powers that the Congress has placed in ‘the Secretary or his delegate.’ ” 400 U.S. at 533, 91 S.Ct. at 544. Again, in Bisceglia the Court, finding no discernible contrary purpose by Congress, upheld the IRS’s authority under section 7602 to issue a “John Doe” summons to a bank to determine the identity of unknown individuals who might be liable for unpaid taxes. The Court again broadly construed the IRS’s summonsing authority in Euge to permit it to compel the execution of handwriting samples. A contrary result, reasoned the Court, would “stultify enforcement of federal law.” 444 U.S. at 715, 100 S.Ct. at 880 (quoting Donaldson, 400 U.S. at 536, 91 S.Ct. at 545). Finally, in Arthur Young & Co., the Court declined to accord a privilege to an auditor’s tax accrual workpa-pers. “We are unable,” wrote the Court, “to discern the sort of unambiguous directions from Congress that would justify a judicially created work-product immunity for tax accrual workpapers summoned under § 7602.” 465 U.S. at 816, 104 S.Ct. at 1502.
Thus, the Court has refused to impose limitations upon the IRS’s summons authority unless it found explicit Congressional directives to do so. We believe that this judicial constraint used to avoid limiting the IRS’s summons authority applies equally in this case and a court should not conditionally enforce a summons. If a court were to do so, it would then potentially have to become involved in the proceeding again at a later date to ensure compliance with the conditions it imposed. There is no evidence of a Congressional intent to burden the “summary” nature of summons enforcement proceedings by allowing the district court to conditionally enforce a summons.
*1350In fact, it appears that the intent of Congress was definitely not to burden the summary nature of the enforcement proceedings with such an inquiry. Rather than enact a statute authorizing the district court to conditionally enforce a summons to prevent the government from violating section 6103, Congress instead enacted civil remedies that allow an individual to bring suit against the United States and provided for criminal prosecution of the disclosing parties. These remedies clearly are intended to deter unnecessary disclosures of confidential information.
In a summons enforcement proceeding, the district court’s only task is to determine whether the summons should or should not be enforced. This inquiry is limited to ensuring that the government has complied with the four Powell criteria, and that its process is not being abused. Powell, 379 U.S. at 57-58, 85 S.Ct. at 255. There is no statutory authority, nor congressional indication that existing statutes supply the authority, nor Supreme Court authority, to allow the district court to make any consideration except whether to enforce or not to enforce the summons. The district court does not have the power to conditionally enforce the summons. If good faith and a legitimate purpose are found to exist, the summons should be enforced. If they are not present, enforcement should be denied. There is no middle ground because to create that remedy would unduly hamper the investigative efforts of the IRS.
Dr. Barrett contends, however, that numerous decisions of this circuit provide district courts with the authority to condition a summons to protect the rights of taxpayers. While some of this authority may, arguably, support this view, most of it clearly does not, and we decline to adopt his position. The ease that appears to most directly support Dr. Barrett’s contention is Dunn v. Ross, 356 F.2d 664 (5th Cir.1966). In Dunn, the court held that a summons under section 7602 could require the production of records for years that were time-barred from investigation so long as the material from those years was relevant for the years that were under investigation that were not time-barred. Id. at 666. In support for his position that a summons should be conditionally enforced when necessary Dr. Barrett relies on the following language in Dunn:
Our decision, therefore, should not be construed as a blanket endorsement of summonses under 7602 requiring the production of a vast amount of books and papers, many of which might be totally irrelevant and the production of which would cause great hardship to the persons at whom such summonses are directed. The District Court has broad discretion in the protection of the taxpayer and of third parties against oppressive procedures by working out appropriate limitations on which records are subject to investigation and the best location for such inspection for all concerned.
Id. at 667 (citation omitted). One reading of the second sentence from this passage could support the view that a district court has discretion in deciding how or to what extent to enforce a summons, i.e., conditional enforcement. However, another reading of this language is that the district court has broad discretion in protecting taxpayers only by determining whether the sought after information is relevant. The relevancy inquiry is one of the Powell inquiries, and it only pertains to whether the summons should be enforced in its entirety. To the extent that Dunn can be read otherwise, to endorse the district court’s ability to conditionally enforce a summons, it is overruled.
Our decision in Venn v. United States, 400 F.2d 207 (5th Cir.1968), is also cited by Dr. Barrett as support for his position. He argues that in Venn this court affirmed the conditional enforcement of a summons to prevent improper use of the summoned information. We do not read Venn so broadly. Venn dealt with the issue of whether an unrelated criminal prosecution of a third party would prevent enforcement of a summons, when the taxpayer had materials relating to that third party’s tax liability. Id. at 209. The court held it would not. Additionally, there was an issue of whether all the material sought was relevant to the taxpayer’s investigation. Id. We concluded that the government had not made such a showing. Thus, the issue *1351in Venn that Dr. Barrett attempts to rely on as support for his position is one that deals with the scope of the enforcement order, i.e., what amount of information would the government be provided. This inquiry is also in the nature of asking whether the material is relevant. The case did not address the issue presented before us of whether conditions would be imposed on the government’s use of the information once it was received. Venn, therefore, does not support Dr. Barrett.
Another decision, United States v. Roundtree, 420 F.2d 845 (5th Cir.1969), is also cited by Dr. Barrett as support for his position. He quotes the following language from the opinion which reads: “Furthermore, courts may limit the invasions of privacy through the individual scrutiny to which a summons is subject for its enforcement through the standards enumerated in Powell of legitimate purpose, proper procedure, relevance, and refusal to allow abuse of the courts’ process,” id. at 851, as support for the conditional enforcement inquiry we ordered in Barrett II. We do not believe this language supports that conclusion. The issue in Roundtree was whether a summons should be enforced, and what procedures were available to the taxpayer to assist him in attacking the summons. The court was not faced with the issue of whether to conditionally enforce the summons. Moreover, the language quoted by Dr. Barrett does not address the conditional enforcement of the summons, but rather it relates to the enforcement of the summons in its entirety.10
In sum, we do not believe that the cases cited by Dr. Barrett give rise to a conclusion that a district court can conditionally enforce a summons.11
V.
We hold that in a summons enforcement proceeding the only issue that the district court can decide is whether to enforce the summons. The court cannot conditionally enforce that order. Therefore, we OVERRULE the holding in Texas Heart that a district court should determine whether section 6103 was violated, and, if so, to condition enforcement on compliance with that section. The issue presented today does not call for us to decide whether a court’s enforcement order may impose conditions respecting the time, place, manner, form or circumstances in which some or all of what is sought by the subpoena will be furnished, or possibly other conditions precedent to the government’s receipt, pursuant to the subpoena, of what it seeks thereby. The summons order in Barrett II is AFFIRMED in its entirety.