AT&T doesn't touch my bandwidth. They don't cap it, they don't filter it - they aren't keeping a database of my URL lookups.
While I doubt that's true even today, it's only a matter of time before they implement bandwidth caps. I don't think any major ISP is not at least trying them out. AT&T started trials last November. http://gizmodo.com/5075831/att-monthly-bandwidth-caps-are-here