I think this could be a good idea, and could stop some threads turning offensive, whilst still being able to discuss and debate topics, but still overseen by the current moderaters.

If a thread is started that seems deliberate to provoke people then a moderator could then turn off the function for the thread starter.

Whilst this may sound like a good idea for the majority of users, there is a large enough minority of users for whom this would be a disastrous idea, so this is not likely to be implemented.