How is it not technically possible to collect information from consumer devices that are connected to the Internet and where the vendors cooperate to provide backdoors (as they do with cell phones)? As for politically feasible, it isn't politically feasible for them to collect everyone's communication via PRISM, yet they are doing it.

Preventing government abuses means paying attention to not just what they've already proven to have done, but also attempting to discourage them from taking likely next steps.