You can see twitch user Indianola (Lndi-Anathema) post an IP grab in the twitch chat which the streamer clicked on. After he clicks on it, the DDoSer, Henkebenke, has his IP and DDoSes him.
Watch as a man dedicates hours of his life to purge buffs from people. He sure got them!
More importantly though, go to 3:42 to watch someone commit a highly illegal act as his toothless friends laugh along with him!