Try the words
Censorship
Prior Restraint
and
First Amendment Violation.
There is a court case, IIRC Supreme Court level, so binding precedent upon all Federal districts, that the US govt. may not use private companies to do things which are Unconstitutional for the govt. itself to do.
I misplaced my link; someone will likely remember it for me.
The lawsuit that President Trump filed against Facebook and Twitter should be epic just for discovery alone. It’ll be interesting to see if the courts continue to ignore constitutional violations that are plain for all to see.