I've grown accustomed to writing longer comments or posts in an external editor, simply because I've too frequently experienced browser crashes, or an inadvertent (or absent-minded) screen refresh. Alt-backspace is my worst offender, as I use that ALL the time in the shell for text editing, whereas in a browser it navigates backwards.

Worst of all, I can't seem to find a way to alter the keybinds, or (more importantly) the mouse-5-means-go-back gesture.