Cool!  That's a good idea.  I may implement it and similar things soon.  Just for posterity, I independently invented CAPTCHA, I think a year before the CMU kids thought of it.  I even began filing a patent while at my startup in the late 1990's, but we ran out of money.  I should have continued, although the situation was murky.  Imagine my surprise a couple years later at the IJCAI AI conferences in Acapulco when the CMU team presented CAPTCHA at an extra presentation at the end of the conference.  I went on a lark because the point of the presentation wasn't clear until I was sitting in it.  Just one of the many things I've thought of / invented that I didn't capitalize on, or give away in a timely fashion.  Par for the course; many people will have similar ideas at similar points in time.

sdw

On 7/14/18 4:50 PM, Steven Schear wrote: