I remember a few years ago there was an initiative encouraging people to take pictures of their hotel rooms as they checked in (to get them in the fresh state) and provide them to a non-profit, with the idea that they could compare those images with photos of persons who were being trafficked and advertised on prostitution sites or in CSAM images to try to identify where the victims were or had been. It seemed like a noble idea but I never heard more about it. I guess this is one of those things where the theory sounds good, but in practice it’s ripe for abuse (as mentioned in this article, initially the tool was open to anyone and there were users on the company’s Discord trying to use it to stalk women).