Comcast Tests a New Bandwidth Throttle

Some Comcast customers experienced unexplained delays in using internet. Congestion caused by a handful of customers who use far far more bandwidth than everyone else made the cryptic slowdowns. They often use P2P protocols like BitTorrent for exchanging whole movie files.
Comcast will test a new Throttle that can identify which Internet customers have been particularly heavy users of bandwidth at any given time and block them.
An article as below is the introduction of the related trouble of Comcast struggling with heavy users .

http://bits.blogs.nytimes.com/2008/06/04/comcast-tests-a-new-bandwidth-black-list/