These sort of posts are usually handled by MindlessElectron, a bot created, and managed by Mitchell. Although, it only nukes certain posts that fit the criteria, and only from newbies.
I am fairly certain that mprep also uses some amount of automation in handling reports. It might not be to the extent that no human intervention is required for action to be taken, however, I strongly suspect that he uses tools to help him handle common report types quickly -- he certainly has the technical expertise (from what I have observed) to create said tools.