There have been several spammers with offers to sell electronics and I think Touch Arcade should make it were you cannot make a new thread until you become a member. Maybe, even a Senior Member.
not sure if it's a good idea..some people join so they can make a thread to ask a question. I know I did.
Just report the thread and it'll be taken care of ASAP Also, it'll be impractical to restrict someone from making a thread. You cant really expect the devs to visit the forums, spam some posts first and then make a game announcement thread.