Before we get out the tinfoil and duct tape on this one, let me emphasize that this is purely speculation until otherwise noted. It seems that The Consumerist has a source that states Comcast actually contracts a company to do their bittorrent sabotaging, which would shoot down most of the explanations I’ve read. Guess we’ll just have to wait on that federal probe.
In the reports about Comcast's disruption of traffic between customers using the BitTorrent file-sharing protocol, it's alleged that Comcast outsources the traffic meddling to a third-party company called Sandvine. Publicly, and in an internal talking points memo leaked exclusively to The Consumerist, Comcast refused to comment on having any relationship with Sandvine.