Correct me on any side of this sentence:
"Your project is aimed to provide a safe and secure way of an image creator --which on its category, a photographer-- to publish and get loyalty of their works, privately."
So if someone uploaded a selfie images, or an image with certain identifiable object or subject on it, intentionally or unintentionally, what then?
Why would anyone upload selfie in CC0 license photo sharing platform ..
Because they think its beautiful, the background are nice, the tone is just perfect, etc? Who knows? Don't you consider that as a possibility? Even one in a thousand chance? And don't you think about a prevention for such scenario? No matter how less likely --but still had a probability-- it'll happen?
As far as I see, the images don't get uploaded directly. There is a mod sitting behind the walls. He probably should be knowing this.
The other thing is that all website that host images has a content removal policy, so they must have it. You can ask for removal of any content with some arguably good reason. They have the contact page.