This is the same comcast we're talking about right? The one that's spent millions lobbying for the right to monitor what their customers do online and sell it to advertisers?
It's a rigged game for sure. Would Comcast and the other ISPs be fighting so hard for these rights if they didn't have Google and Facebook as models of success using them?
Are you sure you are not both? ATT gives you a discount on your monthly fee if you allow them to inject their own ads. It was opt-in, but it would not surprise me if they don't just do it to all users. Plus, if you are using their DNS, I'd assume they are slurping in all of that data.