It depends on the service tier you idiot. If I exceed the limits set by the ISP, then they will throttle me or try to charge more, as per terms of the service agreement you moron.
Usage based pricing is the direct effect of net neutrality you moron. Prior to that wonderful idea, wireline bandwidth was unlimited. So the main reason there are now tiers and caps is because ISPs thought they could bargain with Obama and retain control of usage pricing.
Now tell us again how Google and Netflix eat up all the bandwidth and there's nothing left for the little people.