So, you can no longer assume being anonymous when walking down the street. If your random photo is matched with your profile, you can be basically fully identified anywhere. With all those cameras everywhere, you could be fully tracked.
You could never assume that. The only thing that gives you anonymity on a public street is the fact that you're not interesting. Since most people walk mostly the same paths all the time, it's pretty much guaranteed that if you suddenly started to do something weird, at least some people on the street would recognize you and could - in principle - figure out who you are.
Also consider that your local grocery store clerk probably knows your eating and drinking habits better than you know them yourself.
No need for the images to be public. A police state could match images taken by street CCTV to e.g. the drivers license database and track the citizenry in real time.
You could easily reduce the search space to match a face taken by a CCTV camera by using cell phone location data to limit it to people in the general area...
A police state has always been able to do this. Of course it gets easier by automatic face recognition and the possibility of sharing databases over long distances etc.
The difference from before I guess, is that it's less in your face, and can thereby happen without people noticing as easily.
