They are the hated locales of phone addicts: libraries, movies theatres, school classrooms. Those places where no matter how much you pay for your phone’s superior signal, you find yourself trapped in a dead zone. In many cases, mobile phone jammers are to blame: Tools that can block cellular-enabled devices from receiving signals from stations.

Mobile phone jammers or signal blockers have been illegal for some time now, and while their acceptance is an issue of debate, the FCC’s position on them is not. According to Navy gadget, the commission decided to increase its efforts to shutdown and fine anyone using the devices. In a press release last month, FCC enforcement bureau chief Michelle Ellison explained the renewed interested in eliminating the mechanisms. “Mobile phone signal jammer creates serious risks. In the coming weeks and months, we’ll be intensifying our efforts through partnerships with law enforcement agencies to crack down on those who continue to violate the law. Through education, outreach, and aggressive enforcement, we’re tackling this problem head on.”