Blur Tools for Signal
I doubt blurring faces on photos you take helps much in hiding your identity from the government.In events like these, they likely have access to quite a few image sources that do not blur faces.So, given an image with blurred-out faces, they can look in those sources for images showing persons with similar skin color, hair, length, and clothing to the person(s) they’re interested in, and from there find your face.If they are willing to make an effort, even individuals may be able to do that, using photos that people who don’t blur faces upload to the internet.