No, they wouldn't ban an entire ISP. In my case, I'm stuck with Comcast.
They are the largest cable company in the US. No way would they ever ban it.
I'm not sure what they do, to be honest. I just know they can't very well ban people with dynamic IPs. I'm not very well informed about the inner workings of the uber google elite snuff squads, though.
Hehe... that's kinda funny.
-Michael