Problem: There are so many uploads on Wikimedia Commons that are copyright violations. Some of them are snapshots of some computer screen or some other image like a poster. I estimate that about 3-6% of all files on Commons (most of them probably images) are copyright violations. I already had some files around the time when Commons started that were copyright violations and nobody ever noticed.
Proposed solution: A bot or tool that checks uploaded files and flags them if they are potentially copyright violations
Who would benefit: Wikimedia Commons as such as well as admins