I was passed this article about metered Internet in the Rochester area by Time Warner Cable. It's a pretty hot issue and very unpopular.
Deaf community reacts to Time Warner metered pricing
In short, Time Warner Cable will be implementing metered pricing. When that happens, those who use videophones could be priced out of using them. Watching online videos like Hulu and YouTube adds up as well. Some downloadable videos are in the megabytes, while downloaded DVD movies can be about 4-8 gigabytes.
My question at the moment is how much data is being passed through the lines in a 30 minute session? Many VPs send data at 256Kbps and receive at 384Kbps.
It's a possibility this may be implemented in other broadband markets.
Update April 19:
Check the Victory of Internet Freedom blog post by Sharyn. She reports that Time Warner Cable has backed down from their metering proposal.