I would like to see something similar to patrol, but for all account levels. That would make it much easier to detect all accounts involved in the spam.

Also, I wouldn't mind a "cleanup" of all unused accounts (with 0 posts): ban them all once they're a month old without posts. I suspect many spammers have been stockpiling accounts, as they often use older accounts for their spam runs.

And signatures aren't the cause of spambots bumping ICO threads either, so none of these solutions will work.