It is absolutely possible to identify users who post a lot on a public forum with a real name (e.g. Facebook or the like) as well as Reddit. So say you have some politician who claims to have X, Y, Z values and a Reddit user who has A, B, and C values that are antonymous to X, Y, and Z. By comparing common phrases, as well as by charting when the two seemingly separate users are online, you could say with reasonable certainty that the two people are one and the same, especially if you prompt them carefully to say the kinds of things they would say about neutral topics on both accounts. It would be hard to get 100% certainty, but you’d be close enough to imply it’s them.

AIs (LLMs) just make it faster.

Don’t post about controversial politics if you also post under your real name. It’s not a matter of “mask yourself better.” There will always be tells.