The Dutch anti-piracy outfit BREIN claims to have taken down 75 BitTorrent trackers today. Although most of the sites were relatively small and private communities, together they had more than half a million registered users. This is the first time that so many sites have been taken offline at once.
Anti-Piracy Outfit Shuts Down 75 Torrent Sites | TorrentFreak

Here goes the BREIN again. Maybe some of the shut down trackers weren't so well-known, but the fact that they could close 75 all of a sudden is scary - although it seems all of them were hosted on the same provider (Amenworld), so a single call was all they needed to do to take all of them down.