While some networks are imposing what seem like generous bandwidth limits (2GB/say for Cox Communications and 40GB/month for Road Runner), Comcast is targeting subscribers who "represent (in the sole judgment of Comcast) an unusually large burden on the network." Rather than being given generous or even strict bandwidth allowances, Comcast is judging high volume users against a larger average. The flexible bandwidth cap should scale well as high bandwidth applications become more common, but not knowing how much downloading is too much has to be unnerving for subscribers on the verge of having their accounts suspended.
As cable companies cap, DSL providers like Verizon and SBC Communications claim their services are truly unlimited. However, as P2P networks consume more and more broadband resources, I have to wonder if the days of cap-free Internet access are nearing an end.