If they're using the same AI for every anonymous identity, maybe that's still identifiable to an extent? But yeah.

Hopefully any such AI used by the government can't be admissible as evidence in a court of law (assuming it's neural based and not a bunch of if statements), or at least is only used in pursuing federal crimes. But with the way things are going, who knows.

I was thinking of those writing AIs that rewrite whatever you write to a consistent voice. The ones that students are using to cheat in schools nowadays.

I wonder how difficult that would need to be in practice. Obfuscation just has to be enough that it creates enough ambiguity. All you'd have to do is make things like basic punctuation, capitalization, rate of typos, advanced word count, etc. consistent. Those are things that can be "statically analyzed" from one's genuine writing and be changed on the fly without needing an AI to know the meaning of a body of text.