"The distributed denial-of-service (DDoS) attack on the BitTorrent infrastructure prevented some users from downloading files for up to 10 hours on Wednesday, said the administrator, who asked to be identified only by his online handle, "Lowkee." The target was the central BitTorrent directories, or trackers, which are used by people to find movies, music and other content on the file-swapping network, he said."
As a side note, Suprnova owners seem to be working on a new file-sharing application called "Exeem", currently under beta testing:
"No more web mirrors, no more bottle necks and no more slow downs. Exeem will marry the best features of a decentralized network, the easy searchability of an indexing server and the swarming powers of the BitTorrent network into one program."