How the AP busted Comcast for blocking BitTorrent

In the wake of yesterday's revelation that AP had discovered secret, anti-BitTorrent software running on Comcast's network, a followup story explaining the clever detective work the AP did in rooting out this little shenanigan:
An AP reporter attempted to download, using file-sharing program BitTorrent, a copy of the King James Bible from two computers in the Philadelphia and San Francisco areas, both of which were connected to the Internet through Comcast cable modems.

We picked the Bible for the test because it's not protected by copyright and the file is a convenient size.

In two out of three tries, the transfer was blocked. In the third, the transfer started only after a 10-minute delay. When we tried to upload files that were in demand by a wider number of BitTorrent users, those connections were also blocked.

Not all Comcast-connected computers appear to be affected, however. In a test with a third Comcast-connected computer in the Boston area, we were unable to test with the Bible, apparently due to an unrelated error. When we attempted to upload a more widely disseminated file, there was no evidence of blocking.

Link (via Isen)

Update: And check out thehilarious stupid lies that Comcast Interactive's president told Information Week!