I wonder if there's already a tool that clusters papers by similarity or else how do the reviewers reject a paper on such ground. How do they find it? Do they know them all by heart? Maybe we (the community) can help by creating an open platform that scraps openly available papers and automatically finds and sorts similar ones.

I’m an academic computer scientist. I submit things I review through my institutions cheating detection system. I have found plagiarized submissions this way.

I was not aware of it, thanks for the info. I followed up on the topic and found the famous ones.