Caught him griefing stuff on the server in the last 30 minutes. He stole some torches from around fen's house, and I saw him break a block off it. He then moved on to remove blocks from the building I had just completed, at which point he was shot repeatedly with arrows until he left. Not sure how much damage he did but he was on for about 30 minutes before I saw him so there may be more damage than just this that I didn't notice.