We are inundated with an avalanche of a firestorm of spam posts.
I think I have the beginnings of a solution.
To post you have to register. To want to post you almost certainly have the game installed.
So, as part of the registration process you have an email sent to your registered steam / gmail / “whatever Apple’s store uses” address. Only when you’ve replied to this will your account be activated.
Ok, what obvious and simple thing have I overlooked?
Integration. We don’t have access to a user’s Apple ID, email attached to Steam, or Google Play email. So we have no way of identifying said account status. Best we could do is OpenID/Google Play logins and hope that the user is using that for the right reason.
Makes sense. After all, if it was easy it would already have been done.
When you do find a solution, don’t forget the bit where it seeks out and inflicts mayhem on the spammer. Something like Jay and Silent Bob Strike Back.