For the ones that fill out their profile info (about me, etc), I would like it if our Akismet plugin could eventually start feeding the About me through its anti-spam checkers.
What percentage of these fill out the user info @BCHK ?
There is a fair argument to be made here for checking global IP blacklists on some new user signups – it’s about the only way to tell if they are just spammers who have not spammed (yet) but are creating accounts to maybe eventually do that?
Another possibility is to auto-delete accounts after (n) days who have not visited nor read anything beyond signup. But a lot of site owners won’t like this because it hurts their “stats”. Never mind if the stats are bullshit..