Sorry, "illegal" versus "legal" in America is determined by the courts, not by private corporations.
Didn't you get the memo (2016)? Corporations now write the law, and they don't even prevent for impartiality.
Who are you saying is accused? AT&T or the customers? I don't believe there is any legal proceedings related to any of this?
I think OP's point was that if this bothers you and the recent de-platforming of people and websites does not, maybe you should rethink your position. But maybe I misread OP?