[@robin-w Moderator 4 years ago]

I presume you have ‘anyone can register’ ticked in :

dashboard>settings>general>membership – that will let anyone join, and at that stage you cannot know if they are real or not, so no automatic way to prevent.

I’d suggest you move to a closed registration, so that you can manually join people.

as for getting rid of those in there – you would need some code which would look for all users who have not made a forum post, but this might delete genuine users, so without a forumla to work out who is real or not, it would be hard to code/