I'm guessing they use this alongside CSPRNGs. Would make sense given the theorem that states any random number XORed with even highly-ordered input maintains its entropy.

There are lots of people in the crypto world who have serious issues with XORing random sources together.

I haven't yet seen a good argument why it's a bad idea, and part of me thinks it might be a way to get more software using "rdrand" or other insecure sources unmodified.

I think the bad idea stigma stems from people XORing from the same source. That totally is a bad idea, but if two sources are wholly independent, the maximum entropy in the combined systems is maintained.

To the people that just say it's never a good idea and scoff at any reasoning I'd remind them about OTPs. They are a special case related to this principle of XORing two independent sources together where only one input is random and it is proven mathematically to work.

Pretty sure an attacker would have to observe the array from the same point of perspective as the camera to mount a successful side channel attack.

don't forget the room heating. I'm sure a wall of of 25-100w incandescents can get pretty toasty.

very green.