There's a certain site I moderate where a very high rep user has become downright abusive to other users of the site and the mods are having to constantly delete content to avoid letting the site turn into a constant flame war. Mostly this is in the form of bickering turning into name calling in both edits and comments where downvoting isn't really an option and deleting the offending content isn't that much of a deterrent.
I'd suggest two things that would help the moderators rein this user in:
1) A feature to suspend a user from commenting.
2) When deleting comments, etc. Throw a "Yellow card" which deducts reputation from the user for seriously bad behavior at different levels based on the severity of it.