Trophies in Multiplayer.
I just hate them. At least those trophies you need to have a Platinium. They should be treated like it's a DLC.
It forces you to go only, but some people, do not fancy much online gaming. I am not a big fan of it, a friend of mine is the same.
Simply because you can't manage tour time in the same way. So you are punish basically because you have a life and have schedule to your gaming around it.
Uncharted 2, might be the best case of Online Trophies.