This afternoon we’ve had a flurry of edits in the “vandalism” category on MDC. It appears that a bot of some kind is periodically signing up for new accounts and then damaging pages. Unfortunately, most of these appear to be coming from different IP addresses.
After trying for a while to be patient and just keep up with it, we finally had to ask IT to find a solution. As a result, at least for the time being, IT is going to adjust our MediaWiki configuration to require email confirmation for new user signups.