Why the bloody flour do isps want us not to use the bandwidth we pay them for monthly? Bunch of b$ if ya ask me. Next time your isp gives you trouble, ask them why they don't like providing you the service you are paying them for and why you should keep them as your provider. My suspicion is a few movies on hulu won't make much difference unless you are watching it 24/7 ?
For residential service I think that most ISPs are actually charging for a lot less bandwidth than they advertise knowing that most people won't use all of it and they can over subscribe their network. If you want to get the bandwidth advertised, sign up for "business class" service. It will cost two or three times as much for the same stated bandwidth but you will actually be able to use it. And as a bonus that usually comes with a fixed IP address and terms of service that allow you to run servers.
Basically you get what you are paying for and on a residential service you are not paying enough to get the full advertised bandwidth on a 24x7 basis.