When I asked FCC Commissioner Michael Copps what he found the most interesting of FCC Chairman Kevin Martin’s remarks at CES, he mentioned his surprise at the news that the FCC was investigating complaints that Comcast blocked BitTorrent files. Not that he was upset, mind you—Copps approves of protecting so-called “net neutrality” notion—but Martin had yet to share that info with him. It was news to Comcast, too, although surely they sensed it was a possibility, particularly given Martin’s attitude towards cable operators. Turns out the actual letter to Comcast from the FCC’s Enforcement Bureau, went out Friday and it has been received by Comcast (NSDQ: CMCSA). Ted Hearn has details at Multichannel. My favorite part: Comcast won’t show the letter and the FCC “would not confirm the letter, saying Enforcement Bureau communications of this type were not to be made public.”

AP reported late last year that Comcast, the country’s largest residential ISP, was blocking BitTorrent users on its network. Comcast maintains it manages traffic during peak times, not blocking it, and the only packets that are delayed are p2p uploads. The delays, critics charge, violate an FCC “principle” that users have the right to use apps and services of their choice barring law enforcement’s needs.