Ive got two suggestions.
First, we could have a "Welcome to the SGDK Forums" Thread where new members can introduce themselves and we all can decide if the user is "legit" or not.
Second, in order to create a new user, that person must have a code from somewhere in the SGDK help file. (like for example, what is the first word in paragraph 3 on the tileset help page?) this way, only those who have used SGDK can create an account. you wouldnt have to do this if you are already a member.