If there was a way that you can type in someone's username and it told you how many games you played with them and which games you did. That way, if you see someone that you sort of recognize but you aren't sure whether you should trust them or not, you can go back and check out the games you played with them so you can make a decision on how to handle them in future games.
You would only be able to do this out of your own account (so as to check who YOUVE played with) as opposed to being able to have access to the database for the entire community (so you can check "who's with who"). This would only be a reference material for your own game.
True Noah, I am not suggesting that people use this info as gospel and get revenge for games 5 years ago. It would just help people remember the games you did play with them, and then you can make a decision based upon that if you want, or other factors.