[wiml]

There's a certain amount of censorship of classified information published by (ex-)military, and that kind of thing, but it can be and is challenged in court.

Purely obscene material is also not protected by the 1st, but since the 1970s, the bar for that has been placed very, very high.

The closest I can think of offhand is that for about a year during the pandemic, Twitter suppressed gratuitous COVID misinformation posts, at the request of the government.

[mothballed]

Jordan Derrick (Ashley Dugan) recently had a youtube video on making RDX pulled and criminally charged with "distribution of explosives information to terrorists" for publicly sharing the public domain patented/documented synthesis (going back to a German patent all the way in the 19th century IIRC) of RDX explosives and denied bail for "hate speech" of using the Israeli flag as a doormat (which was actually in the indictment).