Ever been to the Leaning Tower Of Pisa? If you have, chances are you've had your photograph taken "holding it up" with your arms outstretched.
YouTuber 'JegStuffoInfo' here calls it 'troll high-fiving', which essentially means that you high five people while they're offering up their open palms to the sky. Tonnes of fun, we can all agree.
And if this little prank-a-thon has piqued your interest in such childish activities, here's our video gallery of professional prankster Remi Gaillard doing his thing, starting off with this ludicrously popular 'Real-Life Mario Kart' video.