Companies that monitor BitTorrent traffic are a dime a dozen, but AT&T marks the first time that an ISP itself is going to be getting in on the action. The company has just been awarded a patent that will allow it to deeply monitor BitTorrent traffic, though its ultimate use seems to be up-in-the-air. The company could simply want to monitor network congestion before it happens, or figure out which pirated content is being shared the most.
Both of these cases seem likely, as AT&T is one ISP that's part of the Six Strikes program, where an Internet subscriber has up to six chances to stop downloading pirated content. It's worth noting that there, it's third-parties that monitor the traffic, while here, AT&T would be doing its own... and probably at a much greater level than any other company could, given it's what's managing the traffic.
The flowchart above helps explain AT&T's technology. It appears that the company will be maintaining RSS feeds of torrents that it could end up downloading and then search through. While names are going to play a huge role in what the system detects here as piracy, it'll go one step further by digging into the file and making sure it's actually what it says it is - and that it's not simply a virus disguised as the latest Hollywood blockbuster.
How AT&T chooses to use this technology is going to be interesting, because based on the fact that it can identify pirated content quite easily, it seems silly to imagine that the company wouldn't plan to use that information somehow, especially given its wording: "However, some content may be pirated and illegally copied and distributed P2P violating copyright laws and reducing revenue for the content producers and distributors".
We have no choice but to wait and see how things pan out.