How about linking facebook accounts to mygaming accounts
But still having the option to Hide your facebook details when your on mygaming
Then once you've linked it together you will be recognized as a legit non-smurf user, and from there you can be allowed to post?
Some people don't use facebook though, and surely people could use a "fake" FB account? Someone would have to manually check every persons page to assess if it's real or not.
If they really want to root out cheaters, maybe they should make the rules something like everyone who has already had X number of posts in the previous week or month can enter.