XMPP-Scrapper? Well, there is the Report abuse button in the thread actions, so you can mark it as abuse, though i dont believe someone is watching these reports. Most of the documents that were created instead of the discussions are still wasting my Recent Documents widget space As about private message abuse, you can try contacting Benjamin, maybe he can do something about this.
XMPP-Scapper seems quite annoying, but it doesn’t seem that he’s actually being evil. I wouldn’t want to disable him for the behavior which I currently observe.
Have you tried telling the user to stop harassing you?