It's in the nature of the Internet for consumers to use different amounts of bandwidth from month to month, as they try out new things, Castonguay said. A cap doesn't suit that usage, he said. It might be better for carriers to charge extra for a higher quality of service, such as always having one's own packets at the front of the network queue, or let subscribers choose to get large downloads delivered the next morning, he said. That would let the service provider put its network to work during less busy hours.

The upside may eventually be more options for consumers, Castonguay said.

"It's likely that hungrier carriers out there ... will seize this and other attempts at capping as an option to do more interesting things," Castonguay said.

Free Press, a key player in the fight against Comcast's P2P throttling, praised AT&T for telling the government and consumers what it's doing but criticized the idea of the caps.

"Consumers have come to know and love the Internet as something (where) they're encouraged to experiment and encouraged to enjoy new applications," said Free Press Research Director S. Derek Turner. "Even consumers that may not even approach the caps may be discouraged from trying new and innovative services for fear they will go over the limit."

"These companies will ultimately pull their toes back out of the water and give the customers what they want," Turner said: unlimited monthly bandwidth at a reasonable price.