People shocked after finding out what clicking ‘I am not a robot’ actually does

For years and years, people have been clicking the little box at the bottom of a webpage that says 'I am not a robot' without really knowing what it does.

You might assume that it's a check mark which a robot wouldn't be able to spot that would easily let a site know that the thing trying to delve further into its pages was a being of flesh and blood, and not an AI pretending to be human.

This thing is called a CAPTCHA, which stands for 'Completely Automated Public Turing test to tell Computers and Humans Apart' and definitely sounds like they wanted their acronym for catching out robots to sound like 'capture'.

However, the actual function of clicking the 'I am not a robot' button does something quite different to what plenty assumed and it's scaring them a little bit.

As the BBC's QI revealed, ticking the little box is actually letting the site check things like your internet browsing history to determine whether you're a real person or not.

"Ticking the box is not the point. It's how you behaved before you ticked the box that is analysed," Sandi Toksvig explained to the panel.

"So, to be honest, I can’t tell you all the details because they keep it secret because they don’t want people trying to cheat the test, but broadly speaking, you tick the box and it prompts the website to check your browsing history."

BBC

"So let us say, for example, before you tick the box you watched a couple of cat videos and you liked a tweet about Greta Thunberg, you checked your Gmail account before you got down to work – all of that makes them think that you must be a human."

Toksvig went on to explain that the little gizmo had a few other tricks up their sleeve to tell if someone was human or a robot, and even a second test to throw at someone to make doubly sure.

She said: "Checking the box can even spur it to analyse the way in which you moved your mouse across screen. It's slightly spooky, I think."

"Essentially, when you are clicking ‘I am not a robot’ box, you are instructing the site to have a look at your data and decide for itself. If the machine is not sure, that’s when it directs you to click on lightroom pictures of fire hydrants that aren’t there."

Dumitru Gornet / Alamy Stock Vector

This clip has been shared around a bit and the reveal of what the 'I am not a robot' CAPTCHA actually does has left them a little bit freaked out.

"Mind blown," one said, while many others were less than happy to discover what ticking the box actually did.

Someone said it 'feels like an invasion of privacy' and another commented that they 'don't want to believe this'.

Others expressed shock that the CAPTCHA was 'actually invading my privacy', following up their disbelief with a rather succinct 'bloody hell'.

So now you know that next time you need to click an 'I am not a robot' button it's a good idea to fill up your browsing history with some believably human links and move your mouse in a natural way, whatever that is.