Stack Overflow software development site will reject questions and comments that are basically duplicates. It tells you where to find the originals. Interestingly, an AI would be good for removing some of the duplicated trash on a lot of sites.

One thing I like is the questions I answer on Quora are not questions an AI can answer.

I wonder what would happen if you got an AI to filter out all answers that didn't have either (1) some reasoning or (2) some verifiable fact. I wonder how much AI crud that would remove.