The Associated Press reports that Comcast blocks and/or delays P2P traffic when its subscribers try to upload an entire file to another Comcast subscriber.
Comcast's technology kicks in, though not consistently, when one BitTorrent user attempts to share a complete file with another user.
Each PC gets a message invisible to the user that looks like it comes from the other computer, telling it to stop communicating. But neither message originated from the other computer -- it comes from Comcast. If it were a telephone conversation, it would be like the operator breaking into the conversation, telling each talker in the voice of the other: "Sorry, I have to hang up. Good bye."
So much for net neutrality.
Let's see if litigation follows.