The Federal Communications Commission has announced it will fine Chinese company C.T.S. Technology Co. Ltd. for selling signal jammers in the U.S.

It is the heftiest fine in FCC history. The fine was for $34.9 million.

"All companies, whether domestic or foreign, are banned from marketing illegal jammers in the U.S. Signal jammers present a direct danger to public safety, potentially blocking the communications of first responders. Operating a jammer is also illegal, and consumers who do so face significant civil and criminal penalties." said Travis LeBlanc, acting chief of the FCC's Enforcement Bureau, in a statement.

Federal law prohibits marketing, selling importing, or — most importantly — using a signal jammer anywhere within the United States, save for rare exceptions that only members of law enforcement get to enjoy.

In other words, it might be tempting to bust out the ol' illegally acquired signal jammer in the movie theater, but we suggest you resist the urge.