This spam is really getting out of control. I would suggest a "Report As Spam" button on threads, and probably a "Report" button on user profiles. Might as well make it automated, where if a user gets more than a few Reports for spam, automatically hide all of their threads and posts until they can be reviewed by a moderator. That would take care of the current issue pretty quickly.
Out of Control Spam
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Sorry for the trouble, we don't have moderators on 24/7. Spammers got around our protection and were able to post a lot at once. We're actively cleaning it up and updating our detection.