Actually..
...You apparently don't understand how bittorrent actually works. It doesn't go out and "grab all the bandwidth it can". Two things affect how much bandwidth bittorrent will grab while you use it on your computer. 1) The download rate is proportionate to the upload rate you set. Even when downloading a file with over 200 seeds and several hundred peers I have never actually hit the 10 MB/s cap on my cable internet connection. 2) Most cable connections are asymetrical with far lower upload rate than download rate. This in itself guarentees bittorrent cannot just "grab all the bandwidth it can".
Bittorrent has been mad the scapegoat by the music and movie industry but in all honesty more people eat up bandwidth streamming ripped tv episodes and new release movies from sites like tudou and megavideo. Let us also not forget the movie and warez pirates using Usenet. Their downloads truly do eat up every bit of available bandwidth and considering most people using something like Usenext pay a monthly fee they definitely try to get their moneys worth by downloading everything they can.