In case you’ve never heard about them: mouse gestures allow you to execute a command by drawing a figure on the screen with your mouse. For example moving the pointer from right to left while keeping the left button pressed makes firefox go the previous page. The extension that does this is “all-in-one gestures”.
Today I discovered an interesting mouse gesture ‘by accident’. Drawing a ‘C’ character on a web page reveals the cookies it stores on your pc.
Shows me this (highly censored 🙂 ):