Computers have learned to make us jump through hoops | John Naughton

Machines are supposed to be tools that serve human ends, but the relationship is slowly shifting - and not in our favour

The other day I had to log in to a service I hadn't used before. Since I was a new user, the website decided that it needed to check that I wasn't a robot and so set me a Captcha (Completely Automated Public Turing test to tell Computers and Humans Apart). This is a challenge-response test to enable a computer to determine whether the user is a person rather than a machine.

I was presented with an image of a roadside scene over which was overlaid a grid. My "challenge" was to click on each cell in the grid that contained a traffic sign, or part thereof. I did so, fuming a bit. Then I was presented with another image and another grid - also with a request to identify road signs. Like a lamb, I complied, after which the website deigned to accept my input.