Part of the Federal Communications Commission's job is to regulate the airwaves, ensuring that radio devices don't unduly interfere with each other and turn the spectrum into a morass of noise. Generally this entails making sure that licensed radio and TV stations are staying within the frequencies they're assigned and within certain power levels, and also cracking down on people broadcasting in licensed frequencies without licenses. One tool in the FCC's investigative arsenal is the ability to inspect radio gear, like TV stations' transmitters, but the Commission also says that this extends to things like WiFi routers, cordless and cell phones, remote garage door openers, TV remotes, or "anything using RF energy." This means that if you have any of those products, or anything with a radio, the FCC thinks it has the right to search your house (via Boing Boing). The FCC contends the authority stems from the Communications Act of 1934