The concept of “net neutrality’' holds that companies providing Internet service should treat all sources of data equally. It has been the center of a debate over whether those companies can give preferential treatment to content providers who pay for faster transmission, or to their own content, in effect creating a two-tier Web, and about whether they can block or impede content representing controversial points of view.
Currently, Internet users get access to any Web site on an equal basis. Foreign and domestic sites, big corporate home pages and low-traffic blogs all show up on a user’s screen in the same way when their addresses are typed into a browser. The Federal Communications Commission has come out in favor of keeping things that way, but its ability to do so has been in doubt since a federal appeals decision in April 2010 restricted its authority over broadband service.
Some large Internet and telecommunications companies are talking, however, about creating a two-tiered Internet with a fast lane and a slow lane. Google and Verizon, two leading players in Internet service and content, came out with a joint proposal that took a different approach. In a joint policy statement they issued in August 2010 they proposed that regulators enforce those principles on wired connections but not on the wireless Internet. They also excluded something they called "additional, differentiated online services."
In other words, on mobile phones or on special access lanes, carriers like Verizon and AT&T could charge content companies a toll for faster access to customers or, some analysts worry, block certain services from reaching customers altogether.
http://topics.nytimes.com/topics/reference/timestopics/subjects/n/net_neutrality/index.html