It might not be possible to make such a distinction in the near future. In a world where quadrocopters are cheap, and everyone is wearing Google Glass with a ca

It might not be possible to make such a distinction in the near future. In a world where quadrocopters are cheap, and everyone is wearing Google Glass with a camera right in front of their faces - the assumption should be that you're being recorded. We'll need to figure out what the social rules are, but I'm pretty sure "don't record strangers" isn't going to be one of them.