I'm using enigmail and was asked by it to enter my passphrase when I decided I wanted to change that email. So I pressed cancel, but I got a new pin entry dialog. Entering a wrong password didn't help either. And as pinentry (correctly) grabs keyboard input, I could not kill it or do anything else except purely mouse-driven operations. Finally I gave up and entered my password. However what would happen if I had forgotten my password? Or if I let a fried write a mail on my system while I'm away? This would be a great way to make my system unusable. The cancel button should be honoured! I'm not sure if this is an issue in enigmail, gnupg or pinentry. I suspect it's enigmail, though.
Seems to be resolved in more recent versions.
