Ref T13215. We're a long way away from a comprehensive approach to abuse, but here's a small step forward: allow users to be "Banished", which hides their comments, profile, and profile image.
This acts like a super-disable: you can't be banished without also being disabled (and unbanishing un-disables).
Largely, this just makes my life easier in doing some cleanup on secure and admin. It may also make life a little easier for other open source installs, since they can deputize lieutenants with "Can Disable Users" which is fully reversible but can clean up some of the most obvious badness of spammers/vandals. This change moves us slightly toward T12877.
I probably didn't get everything and if there's still some way to pull banished users' comments (e.g., transaction.search) that's fine, we can tighten this up over time. It isn't a security/policy issue to let this stuff leak, it's just a nice-to-have to clean it up.