"Comcast is engaging in substantial network neutrality violations. Specifically, Comcast is secretly degrading innovative protocols used for transporting and sharing large files," Free Press and Public Knowledge said in a complaint filed Thursday.

The groups charged that Comcast's actions violated a 2005 FCC policy statement guaranteeing consumers "access to the content, applications, and services of their choice."

Comcast: 'We don't block'

Comcast responded to the complaint immediately. In a statement attributed to David Cohen, Comcast's executive vice president, the company said, "Comcast does not, has not, and will not block any Web sites or online applications, including peer-to-peer services, and no one has demonstrated otherwise."

Cohen said Comcast does "engage in reasonable network management to provide all of our customers with a good Internet experience, and we do so consistently with FCC policy."

Comcast quibbled with the complainants' charges that Comcast's "bandwidth shaping" violates the FCC policy statement, saying that under that document, principles of unfettered access are "subject to reasonable network management." The FCC "clearly recognized that network management is necessary by ISPs for the good of all customers," Cohen added.

A Demand for Action

Free Press and Public Knowledge called on the FCC to take action to enforce the principals laid out in the 2005 document. According to the complaint, the FCC has said "it will not hesitate to take action to address" conduct that violated the policy principles. The complaint charges that Comcast not only violated the FCC's principles of open access and competition but also engaged in deceptive practices.

"Comcast deceived consumers by repeatedly denying that it was degrading peer-to-peer applications (though it was degrading these applications) and by degrading the applications in ways designed to be secretive, including spoofing and jamming traffic," the groups said.

The groups called on the FCC to issue a temporary injunction requiring Comcast to stop degrading any applications. They also asked for FCC to assess the maximum penalties against Comcast -- $195,000 for each consumer affected by the discrimination.

Net Neutrality Debate

The complaint is based on an Associated Press investigation that discovered that Comcast was degrading network traffic in certain protocols, including BitTorrent, Gnutella, and even Lotus Notes. Of particular concern was the fact that the company was doing this by sending reset packets that appeared to be coming from the users themselves. Essentially, Comcast was impersonating users in order to interrupt connections.

The controversy is likely to reignite a debate over network neutrality legislation, an issue that hasn't received much attention in Washington since it erupted last year. On the SaveTheInternet.com site, Free Press argued that in the absence of legislation protecting network neutrality, the FCC must respond to Comcast's tactics.

"The Commission now faces a clear choice," Free Press wrote. "It can either side with the interests of consumers and for an Internet unfettered by corporate gatekeepers, or it can let companies like Comcast, Verizon, and AT&T erect walled gardens and destroy the most democratic communications tool in history."