Certainly, if ISPs can access your data, they would like to. Its basically free money. But its not a life-or-death situation for them, and thus my (somewhat uneducated) guess is that there is less management focus on things like deep packet inspection and consumer targeting. They can also jsut jack up prices or sell more subscriptions. At Facebook, on the other hand, selling ads is priority number 0. Its the only way to make money. So I'd worry more about Facebook seeing my traffic.