I don't think I understand your point about them impersonating users? It seems to me like an account gets created for everyone using the portal. It then provides you a password and you can start using that account. I tried it just now and it seems like your account gets flagged as bot on creation automatically. So most people posting from that domain, might just not have unchecked that "I'm a bot"-tick and are actual former Reddit users.

Creating an account doesn't make a user active though, but for the question if a bot posting stuff counts as an active user or not, I honestly can't say.

[–] shrugal@lemm.ee 3 points 11 months ago* (last edited 11 months ago)

Afaik the bot auto-creation is disabled now, but it used to mirror some Reddit subreddits by automatically creating bot accounts for every Reddit user posting in them, and using that to post the same content in a Lemmy community. That's how the instance got over a million users, pretty much all of them are bots that do whatever the Reddit user with the same name is doing in one of the mirrored subreddits.

What you are describing is another part of the plan: Allowing the original Reddit users to take over their mirror accounts on Lemmy. Apparently it just creates accounts for them if no bot exists yet.