Has anyone thought of using .mousemove() (jquery) to detect spam bots?
Because (I'm assuming) spam bots wouldn't need to move the mouse while navigating a website (and therefore wouldn't) and normal users do, couldn't you use this to trigger some extra security to stop them? (Like a harder validation that is to time consuming or annoying to serve up to everyone)
Admittedly, this could cause some problems for mobile users... but maybe you only run it for non-mobile devices.
//set not a spam bot