It started as a trickle but it's become a deluge now, and I've been deleting posts and threads like crazy daily.
There are all sorts of scripts out there that might work, or might break things because they might be version dependent for instance, but I thought the simplest thing to do was a small policy change for new users as it seems the bots can break the Captcha.
New users will now be asked the following question upon posting.
All I can say is, that if you don't know the answer (or can't admit it)........maybe you're in the wrong place."What was the best microcomputer brand of the 80s?"
Hopefully that will fend off the spammers.
Edit: 1 week later. It appears to have worked.