HBO is now obstructing the downloads offered by other people. BitTorrent downloads are peer-to-peer, but the peers are introduced to each other by a tracker (“you’re looking for Rome Season 1 Episode 2, talk to 127.0.0.1”). HBO runs peers that tell the tracker they have all the chunks of the show, but then send garbage data when a downloader requests a chunk. The downloading client can detect that it’s garbage and will try another peer for the chunk, but the end result is that it takes much much longer to download shows.
I would care more if I didn’t have TiVo.