Thinking like this is a problem. The question isn't "is it possible for people to X". It's "will average citizens have the knowledge, time, and energy to X".
99% of XBox owners will not physically unplug the XBox every time they are done using it because of hazy privacy concerns. Suggesting that a few people could is worse than doing nothing. Those with the knowledge and skill to understand the problem will be inclined to solve the problem only for themselves. A bunch of others will use the "they could just unplug it" line to blame the average user for being insufficiently dedicated/savvy. It dissipates the energy for solving the problem properly. And if the NSA is using the Kinect cameras, then they'll be perfectly happy with photos of 99% of users.
As an example, consider the iPhone. Smartphones existed before it. But by packaging the tech in a way that anybody could use it, they made smartphones mainstream. If we want to make privacy mainstream, we need to do something similar, not fall back on blame-y non-solutions like telling people to unplug things.
