Whether we're trying to log into an email account or do some online shopping, we've all thoughtlessly clicked on the innocent looking 'I am not a robot' button.
While almost every internet user is familiar with clicking all the squares containing crosswalks or typing out a wiggly code, very few of them actually know what the 'I am not a robot' button does.
So when a clip from the TV show QI resurfaced on TikTok explaining the tick box's mysterious function, it was unsurprising that many people were shocked - and that many more of them weren't happy.
In the 2020 episode of the UK panel show, host Sandi Toksvig informed guests that ticking the box actually invited a website to inspect your internet history.
"Ticking the box is not the point. It's how you behaved before you ticked the box that is analyzed," Sandi explained.
Watch the full explanation below:She continued: "Broadly speaking, you tick the box and it prompts the website to check your browsing history. 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."
"Checking the box can even spur it to analyze the way in which you moved your mouse across screen," Sandi added, saying: "It's slightly spooky."
The clip was shared on TikTok by Aussie radio hosts Fitzy and Wippa. They included their astonished responses in the video, which has racked up over 5 million views.
"I had no idea," one said, while the other replied: "This really disappoints me."
People in the comments section were no less shocked by the knowledge.
"That feels illegal," one commented. Another wrote: "WHAT?????"
"You mean I got to also delete my browser history before clicking I'm not a robot," a third person added. A fourth chimed in: "What's her source?? (I don't want to believe this)."