I'd also add, on an unrelated note, that if the concern is bandwidth usage, which is what the article says, I don't see why the ISP doesn't just throttle users, based entirely on bandwidth usage. Like, sure, there are BitTorrent users that use colossal amounts of bandwidth, will cause problems for pricing based on overselling bandwidth, which is the norm for consumer broadband.

But you don't need to do some kind of expensive, risky, fragile, and probably liability-issue-inducing attack on BitTorrent if your concern is bandwidth usage. Just start throttling down bandwidth as usage rises, regardless of protocol. Nobody ever gets cut off, but if they're using way above their share of bandwidth, they're gonna have a slower connection. Hell, go offer to sell them a higher-bandwidth package. You don't lose money, nobody is installing malware, you don't have the problem come right back as soon as some new bandwidth-munching program shows up (YouTube?), etc.