Douglas Walburg faces potential liability of $16–48 million. What heinous acts caused such astronomical damages? A violation of 47 C.F.R. § 16.1200(a)(3)(iv), an FCC regulation that enables lawsuits against senders of unsolicited faxes. Walburg, however, never sent any unsolicited faxes; he was sued under the regulation by a class of plaintiffs for failing to include opt‐out language in faxes sent to those who expressly authorized Walburg to send them the faxes. The district court ruled for Walburg, holding that the regulation should be narrowly interpreted so as to require opt‐out notices only for unsolicited faxes. But on appeal, the Federal Communications Commission, not previously party to the case, filed an amicus brief explaining that its regulation applies to previously authorized faxes too. Walburg argued that the FCC lacked statutory authority to regulate authorized advertisements. In response, the FCC filed another brief, arguing that the Hobbs Act prevents federal courts from considering challenges to the validity of FCC regulations when raised as a defense in a private lawsuit. Although the U.S. Court of Appeals for the Eighth Circuit recognized that Walburg’s argument may have merit, it declined to hear it and ruled that the Hobbs Act indeed prevents judicial review of administrative regulations except on appeal from prior agency review. In this case, however, Walburg couldn’t have raised his challenge in an administrative setting because the regulation at issue outsources enforcement to private parties in civil suits! Moreover, having not been charged until the period for agency review lapsed, Walburg has no plausible way to defend himself from the ruinous liability he will be subject to if not permitted to challenge the regulation’s validity. Rather than face those odds, Walburg has petitioned the Supreme Court to hear his case, arguing that the Eighth Circuit was wrong to deny him the right to judicial review without having to initiate a separate (and impossible) administrative review. Cato agrees, and has joined the National Federation of Independent Business Legal Center on an amicus brief supporting Walburg’s petition. We argue that the Supreme Court should hear the case because the Eighth Circuit’s ruling permits administrative agencies to insulate themselves from judicial review while denying those harmed by their regulations the basic due‐process right to meaningfully defend themselves. Further, the Court should hear the case because it offers the opportunity to resolve lower‐court disputes about when the right to judicial review arises and whether a defendant can be forced to bear the burden of establishing a court’s jurisdiction. These are important due‐process implications raised in this case, and the Court would do well to adopt a rule consistent with the Eleventh Circuit’s holding on this issue—one that protects the right to immediately and meaningfully defend oneself from unlawful regulations. Otherwise, more and more Americans will end up finding themselves at the bad end of obscene regulatory penalties by unaccountable government agencies, with no real means to defend themselves.