Occasionally, I receive invitations to join a Steam group from people I've never met, and which are most likely just sock-puppet accounts to begin with. However, 99% of the time, none of my friends are in these groups, which makes it rather pointless to join them (and add to event spam).
Am I able to restrict group invitations so that they only originate from friends? Other options would be to restrict invitations to only those groups that already contain a friend, or off entirely.