We need a feature that allows us to automatically block users that are unsharing at least 90% of their files.
It's becoming quite a big issue with users essentially paywalling their files, while also having free access to yours, due to the fact that there's no way to catch them before they've already downloaded something from you. It's even more amusing when you read their profiles. They're almost angry when they write it, explaining how leechers are bad and that we need to browse their wantlist, so we can trade something with them that they also more-than-likely got for free.
Coming from someone who actually does buy and share a lot of music, it's offensive to see these people trying to take advantage of myself and others. I don't even have an issue with sharing stuff with other users who aren't sharing anything. I'm sure I was in the same boat when I was a little kid. It's the fact that these people believe they are somehow better than everyone else which triggers me more.