I think the operative difference here is that in the case of the little league photography, the cameras are not fixed in place, are temporary, and are not set up with the intent to capture the identity and actions of everyone in the background. Fixed-installation cameras are permanent, do attempt to capture all possible subjects in its frame, and have an alternate, obvious intent to identify them all. I don't think a Private investigator, paparazzi, or parked police cruiser on a stakeout represent anywhere near the same practical or legal problems as fixed, always-on surveillance cameras. As such, this seems to me like a good place to draw the line.