[BeefWellington]

In a roundabout way libel and slander laws are a violation of the first amendment.

They're civil actions but it's the government through the courts that finds you guilty and imposes punishments, seizing assets, etc. It's very hard to win cases on those things as the judiciary does its best to still make it work within the structure of the constitution but it does nonetheless restrict my ability to say "viro eats kittens" without possible penalty imposed by the government.