Much of the time when I visit the site there is at least one banned spammer, often banned even months ago, active on the site.
They can’t post or do anything else, so why are they here?
Is it some sort of bot view?
Otherwise it makes no sense.
I imagine they are auto-bots, possibly coming from an infected computer hosting a spam virus. They also seem to target specific threads that have “soft” deleted posts, or spam posts otherwise invisible to most posters that are not admins…