They were working directly with Twitter moderators and using their influence to get those mods to remove posts (posts that had nothing criminal in them) and to suspend users (users that are law-abiding US citizens).
If they weren't violating the First Amendment, they were butting right up against it. I wish we could get beyond the point of arguing whether or not this happened. It happened. At this point, I'd like to hear a coherent argument for why people think this behavior from our government, is acceptable.