As stated above, definitely report bad things. We check it multiple times per day and are quick to ban. I don't like the idea of having a flag for the average downloader because it can be easily abused.
Going forward we're working on adding automated scanning for new uploads so we can detect things before anyone else sees them.
From the pages that have gone up recently, it seems like it's one person stealing and re-uploading games. We've been banning their accounts as we uncover them. User reports help us with that a lot.