Suggestion for adding friends (and possible elo boosting spam solution)

Most of the people I add, are either friends of friends or people I played with recently. The same goes for people who add me.

I'd like to see this information when someone sends me a friend request, the same as when someone sends me a game invite through the suggested players feature. If there were a toggle to ONLY allow friends of friends, and people I've played with recently, to add me, "get an elo boost!" spambots wouldn't be able to add me any more. Of course, I need to be able to disable this if I want to add an IRL friend.

edit: additionally, perhaps people I've talked with on Boards should be allowed to send me requests, and people I've been in chat rooms with.