This genius prank was posted on YouTube yesterday by user LAHWF, and is already pretty popular with more than 100,000 views.
Andrew Hales at LAHWF prides himself in creating random awkward moments in public, and this is his latest creation.
The concept is pretty simple: ask someone if you can borrow their phone, start talking on the phone, and then slowly start drifting away as they glaze at you in owe, not knowing what to do or say.
A natural self-preservation instinct kicks in, and they will wish to come after you and retrieve their most prized possession, but it is likely that fear of social awkwardness will stop them. After all, it isn't polite to doubt a stranger's pure intentions and rudely attack them after first displaying kindness and generosity.
The look on these people's faces as they get pranked is priceless, and it is sure to make your day if you do decide to try the prank.