Haha, very interesting.
I think that's a clever strategy... Give your opponent a fake masterplan that makes him think about a defense he doesn't need (it's pretty evil).
But still, I get your point, I guess it would be nice to have a delete button for certain chats.
Either I've unwittingly invented a new form of suicide chess, or I've found a good reason for a "delete" button in the chat window.
Has anyone else accidentally posted their strategic masterplan (i.e. private notes) in the chat window for their opponent to see? No? I have, twice.
Luckily my ideas were rubbish so neither time did it really matter.