I've commented on this quite a bit on a friend's journal. But having done that and also having read comments from others and having some extra knowledge in general I figure I would make a post out of it as well. Recently comcast has made official that they have a 250GB a month cap.
First to put this into perspective. A few of my readers may remember that I was talking about this sort of thing a while back when I was talking about the state of broadband in rural areas. I talked about a few alternatives and how they impose such restrictions. Examples are most wireless internet services such as sattelite and cellular. It varies from company to company but most of those impose bandwidth caps. When I was on Wild Blue I had to put up with a 16GB a month cap. But it wasn't as simple as that. It was a rolling cap and you start getting warned when you hit 80% of it which actually turns out to be 13GB. A rolling cap means you don't get a fresh start each month. So if you for example download 1GB on day one it wont get "rolled off" until day 31. Same thing for the next day and so on and so forth.
Other cable companies such as Cox
also have restrictions placed on their internet service. According to that page the "Premier" account has a 60GB downstream; 15GB upstream limitation a month. I don't know if they enforce it.. some ISPs have one but they don't enforce it. Upon further reading it seems they have that in place simply so that they can encourage people to move up to a higher account. Comcast had 200GB unoffically before but I don't know if they enforced it as I don't think I have ever hit it. Some companies have caps but they also have accounts that are unlimited. WiMax for example has this. Other ISPs like mine don't have a limit but they reserve the right to terminate your connection if you are putting such a load on their system that it interferes with everyone else's service.
Back in the day with dialup they used to charge people by the minute and people used to get disconnected a lot because they had restrictions on how much time you could be on in a single session. I've also caught wind that in europe and other places people have to put up with bandwidth caps such as 20GB a month or less.
So far no DSL company in the USA has such restrictions that I know of (I suggest reading the terms of service for your ISP.. I have) or plans on making them. Of course that may not stop people from worrying but at least for the time being that's the case. It seems to me that the cable companies in the US are doing this because they don't want online video to compete with their cable TV offerings.
However, even though Cable is doing this it doesn't automatically follow that others will. Again DSL in the US doesn't. An SBC (now AT&T) DSL representative has been quoted as saying that his company did not see heavy file-swapping activity as "a problem to be resolved." That and slowly but surely alternatives are being rolled out such as FiOS
(fiber opic on site) which doesn't have such restrictions. Unfortunately it isn't yet in a lot of areas like mine. However, some groups of people in certain communities are getting together and forming their own ISPs such as La Cañada
It's also possible to do this yourself and certain companies like speakeasy have programs specifically for this purpose. If you get enough people together to cover the cost you can lease a T1 line and share it with them. I was wondering about this before and I found that it's actually a viable thing that people have done such as that community I liked to above. It's just like Municipal COOP utilities. That's if push comes to shove. The internet isn't just a single entity so no single company can control it.