I'm very suspicious of Comcast too. They've had hostile policies in their Internet management for as long as I can remember, going back to the days they'd forge RST packets because they didn't like customers using BitTorrent.

OTOH as the article says, 'Joining Mozilla's program means that Comcast agreed that it won't "retain, sell, or transfer to any third party (except as may be required by law) any personal information, IP addresses, or other user identifiers, or user query patterns from the DNS queries sent from the Firefox browser'.

I assume Mozilla will audit and keep Comcast honest here, or at least try. I just am left wondering what loophole Comcast has found.