I don't know how well obscuring facial features will really work. There might just be too much information. Partially obscured face, body dimensions, clothing, location, time... I think it might be a loosing battle.
Who wants to do that every day? Also, how long before we can out-calculate it? Right now we can already match things like gait patterns and multiple biometrics (eg height, relative length of limbs) well enough for many purposes using probabilistic systems (eg your metrics match 3 people but the other two are on different continents so I'm 99% certain it's you).
I don't know how well obscuring facial features will really work. There might just be too much information. Partially obscured face, body dimensions, clothing, location, time... I think it might be a loosing battle.