My guy, what the hell are you even talking about?
Parler existed solely because right wing fanatics, Qanons and Nazis couldn't handle being the object of constant ridicule and attention based of how sh*tty their opinions are on the rest of social media. It was literally a safe space for some of the most horrible people but was allowed to exist before it was used to plan, coordinate and ultimately contain evidence of a coup.
If law enforcement had to rely on catching people in the act of a crime and there investigation ended there, jails and prisons would be empty.