A local llama2 or openassist install could keep him off the grid, if this needs to be clandestine.
Those required logins always end up being tied to one phone number, and VoIP numbers are always blocked. So they have a real name, anyone can look up the name on the account, no special access needed.
If you don't want every AI interaction tied to your real name, there's ways to do it. 👁️
I use Claude.ai a lot, and I like it. It can and will gin up a lot of nonsense, on occasion. I've asked it some pointed questions on arcane subjects I know details about, and it's spit out a pack of crap. I always preface my query with a statement asking Claude to admit when it doesn't have a factual answer, rather than making one up out of whole cloth. Seems to work.