Only if you use it to interfere with US government communications (Title 18, Section 1362). If it only interferes with other people's communications, that's ju

Only if you use it to interfere with US government communications (Title 18, Section 1362). If it only interferes with other people's communications, that's just a regulatory matter (47 U.S. Code § 333), and practically speaking the FCC will only fine you if don't fix it or stop using it after you've been notified.