I think at least right now this is reasonable: It's off by default, and if you choose to turn it on, they don't use it for anything themselves, but Comcast is disclosing that it may be forced to give the data over with a legal request.

If I was advising Comcast, I'd tell them this is a dumb thing to introduce because just the perception of bad behavior is not worth any particular benefit, but whatever. I can't imagine someone deciding they want a Comcast plan because it offers this, and there's no way for them to monetize it without almost assured legal backlash.