BitTorrent and similar protocols have many legitimate uses. I believe the film and music industry plan was merely to search for matching bitstrings of the form

BitTorrent and similar protocols have many legitimate uses. I believe the film and music industry plan was merely to search for matching bitstrings of the form <MP3_header><known_copyrighted_payload> and subsequent known bitstrings. Even the lamest private key encryption defeats such matching. Regarding oversold bandwidth, it has happened since the advent of 33kb/s modems, got worse with 56kb/s modems and has become farsical with broadband.