Suggestion: Karma on profiles?

Hi,

I suggest profiles to have a upvote/downvote button, so people viewing a profile can upvote/downvote its karma. This way, after having a terrible game with someone toxic, we can know if he is like that all the time or if it is only once or twice a year. To limit cheating on this karma value, only logged people could upvote/downvote

Just saying, it may help people being nicer online