In another bicycle discussion forum I encountered a thread about possibility to damage carbon frame by sitting on top tube while stopped.
I see some sense in it, as generally tube walls are a lot thinner in the middle to save weight and are not designed for this kind of load. The problem is, I have not seen any warnings from manufacturers about this habit, nor there are stickers on the frame suggesting to not do it.
So the question is - Is this a real problem, should I change my habits?
UPDATED: There is one local person who does carbon repairs, he claims that he has repaired multiple frames which had been damaged this way.