Comment An article from Voxel on the probelm (Score 1) 434
They're a customer of Level 3 & this guy gives his analysis of the issue (found in followups to the NANOG posting)
http://www.voxel.net/blog/2010/12/peering-disputes-comcast-level-3-and-you
Suggest you just sit there and wait till life gets easier.
