Comcast continues to slow down customers' connections to some peer-to-peer applications, using hacker-like techniques against its own subscribers, according to a report released by the Electronic Frontier Foundation.

But Comcast officials, first accused of blocking peer-to-peer application BitTorrent and other traffic in an October Associated Press story, insisted they're not stopping any Web traffic from getting to their customers. The cable broadband provider does manage its network, which would slow to a crawl if it did not manage bandwidth-hogging peer-to-peer connections during times of heavy congestion, a company official said.

At times, Comcast will delay peer-to-peer traffic, but the traffic will eventually go through, said Charlie Douglas, Comcast's director of corporate communications.

"Comcast does not, has not, and will not block any Web site or online application, including peer-to-peer services, and no one has demonstrated otherwise," Douglas said. "We engage in reasonable network management to serve all of our customers with a good Internet experience."

But the EFF defined Comcast's actions differently. Comcast, the second largest ISP in the United States, uses a technique called packet forgery to slow some subscriber traffic, the EFF said in a report released Thursday. Comcast appears to be injecting RST, or reset, packets into customers' connections, causing connections to close, the EFF said.

The EFF's own tests confirmed tests run by the Associated Press and others that said Comcast was disrupting traffic, the group said. The packet forgery techniques can cause several problems, depending on the applications a customer is using, the EFF said.

"One objectionable aspect of Comcast's conduct is that they are spoofing packets -- that is, impersonating parties to an exchange of data," the EFF said in its report. "Comcast is essentially deploying against their own customers techniques more typically used by malicious hackers (this is doubtless how Comcast would characterize other parties that forged traffic to make it appear that it came from Comcast)."

Comcast's action is worse than if it dropped a proportion of packets during times of congestion, the EFF said. "Comcast is essentially behaving like a telephone operator that interrupts a phone conversation, impersonating the voice of each party to tell the other that 'this call is over, I'm hanging up,'" the group said.

The IDG News Service is a Network World affiliate.