It would be nice to have some capcha alternatives 

By the way, I did disable required avatar upload on sign-in. I set it back to required to see if that makes a difference.

Awesome, I was just thinking it would be nice to have something like that. Requiring avatar upload on sign-in seems to have helped on my site, but if I get any new spammers I'll for sure be interested in that plug-in.

Quote from Paul Cuffe I have a new plugin to help stop spammers on join page, you setup a question on the profile join page, tell the plugin what question to use and you can setup if people need to leave the field blank or enter a fixed word (Safe word) to show they are human ie:

Are you a spammer? (please put NO) 

on user registering it will check the answer given and if not the "safe word" or if you setup to be blank, it will take what action you tell it to do, suspend profile, delete ect

it hopefully will be live on store within a few days, or if you want I can send you a copy privately via PM ($5)