Lately I've been annoyed by the fact that whenever I clicked somewhere on a page in Firefox a blinking curser would appear.
At first I thought it was because of the html was made editable somehow, maybe because of a plugin. After disabling all plugins and not fixing it, I turned to google and luckily found the "issue".
I've simply managed to hit
F7 at some point. which turned on Firefoxs 'visual feedback selection' as describe here.
F7again and it stops.