A lawsuit filed this week in a California Superior Court alleges that Comcast intentionally interferes with Internet file sharing and blocks or slows some applications to a "mere crawl."

The 22-page complaint, filed in Superior Court on behalf of Comcast subscriber Jon Hart of the San Francisco Bay Area, said that Philadelphia-based Comcast has a practice of "severely limiting" the transmission speed of peer-to-peer file sharing and Lotus Notes e-mail. It calls the practice unlawful and fraudulent.

The complaint also said that Comcast's advertising, which claims its high-speed Internet service is "lightning fast" and "mind-blowing," is false and violates the California Consumers Legal Remedies Act.

Hart is represented by attorney Mark Todzo and other attorneys at San Francisco-based Lexington Law Group LLP who have requested class-action status for the lawsuit on behalf of other affected Comcast customers.

A Comcast spokesman said Comcast has not yet been served with the complaint and did not comment on it directly. However, a Comcast spokesman said the provider does not block peer-to-peer services, although it does manage the network to prevent heavy users from slowing down speeds over the entire network, which serves nearly 13 million subscribers.

"We engage in reasonable network management to provide all of our customers with a good Internet experience, and we do so consistently with [Federal Communications Commission] policy," the spokesman said in a statement.

A coalition of consumer groups formally asked the FCC in early November to force Comcast to stop interfering with file sharing, and parties in the coalition urged the FCC to fine Comcast for each affected subscriber. The FCC has not issued any statements on the request.

The complaint does not indicate specific times or dates when file sharing or Lotus Notes was slowed down. However, the complaint does say that Comcast defendants "actively and intentionally slow and/or block the ... applications by sending hidden messages to computers that are running file-sharing applications. These hidden messages appear to the computer as coming from the other computers with which it is sharing files, telling it to stop communicating. The result is that file-sharing applications are completely blocked or severely impeded."