Seldom do look behind the scenes of how technology works. The Google reCaptcha asks us to confirm we are not robots. Do we get the chance to ask if Google is human? Data that reCaptcha collects, Clockwise from top : An entire screenshot of the page viewed, mouseclicks on the screen (shown here as heatmap), the language your browser is set in, your browsers plugins, all your google cookies, and javascript/css on the page you visit. All the information combined can give Google a unique profile of who you are. Finally, I had to actually do a sketch, instead of just screenshots: A little Googlebot vacuuming the data from the internet.