They wouldn't - can't possibly - have a program of mass-surveillance that would be made much less effective by this, could they?
When I was working in factories I used to do a lot of quality control work.
When you have stuff that is clearly within spec, it's easy to sort. When you have stuff that's clearly out of spec, it's easy to sort. When you have stuff that's borderline, it can take a lot longer than it should to sort. In or out of spec might take a second, but just in/just out might not (spec can involve size but also paint/plating finish and other things. If the spec calls for a minimum plating thickness of 10 microns and it's clearly 15 or more across the surface it's easy to see, but if it's 10 across several points you have to look at it more closely to make sure at no point is it below 10)
Another way to look at it - when you have 5 pictures of a scene it's easy to find the best one. When you have 500 pictures of a scene, it's not easy to even begin.
All surveliance programs are ruined by too much material to work with.