They do. It's used in games very often for example. However, you have to cover this in your EULA (or whatever) and have to have fallback (either optional or automatic) because many ISPs would block such traffic.
AT&T does. My internet would become unusably unstable every time I torrented, so I called them about it. They said they blocked torrents to "comply with the law" or somesuch BS, nevermind that I was attempting to download a Linux distro.
Can you elaborate on this? My current ISP definitely shapes torrent traffic to the point where it is impractical to download anything larger than a few KB.
