I was thinking also about blurring the picture/video.
2. Contour lines only
3. Windowed/Striped (only showing like 10-25% of the photo)
If 2/3 of the moderators above agree that it's a bad photo, it moves onto stage 4:
4. Color filters - Break the photo down into k-means color clusters, moderators choose which colors to see. They can see 100% of the colors, or one, or two, or however many they need.
If #4 agrees, the photo goes into the round folder.
No need for anyone to ever see the whole photo. It'll be pretty obvious that something was violating the TOS without anyone being able identify anything specific about the photo.
We're not talking about 'beyond the shadow of a doubt' here, we're talking about 'yeah, that's probably not ok.'