He is currently in possession of stolen Bitcoins from the Linode hack and any coins purchased from him will not be accepted by MtGox or anyone in the Bitcoin community.
I wasn't aware Mt. Gox retained the right to pick and choose which Bitcoins they'll accept. Where can I find their policy on this? What happens if I transfer them coins they choose not to accept? How can Bitcoins remain useful as a currency if people start picking and choosing which coins they'll accept? This increases everyone's risk when accepting Bitcoins to intolerable levels.