Most likely he dictates this shit to his social media handler on the jail phone. That's assuming these messages are even coming from him.

Screens keep prisoners mollified, cell phones keep prisons from nickle and diming prisoners. Idk if this is tate or his lawyer or whatever posting this.

The only reason not to give people cell phones is if their crime was facilitated with one or if they were being egged on to commit crimes online/or by persons they know.

The risk is of course that the outside world can manipulate things in in the prison

Pretty sure a lot of prisons allow computers and phones even in the US so he probably is just allowed a phone or computer with Internet access. Frankly given the nature of this pissbags crimes I am of the opinion such privileges should be revoked. Mind I am also of the opinion he should be be made a paraplegic and forced to crawl all along the 15 without any clothes, mind you it's a solid 90+ where I am in California so it's probably a lot worse on most of the freeway.