Optical masking
Turns up in films and some sci-fi books.
The idea that you wear something that essentially makes it impossible for the camera to clearly see your face (either infrared LEDs - though, most decent cameras do have IR filtering), or some other form of non-visible light)
Surely can't be that long until someone comes up with something. I know i've seen at least one video of people using an image on a card that prevents at least one type of facial recognition software from detecting you're even there. No idea how viable that would be unless you knew for sure the weaknesses of the system you would be recorded by.