In this video Darius Groza takes advantage of tourists taking forced-perspective photos of themselves propping up the Leaning Tower of Pisa by running up and giving them high fives when they're not looking: Brilliant.
This is exactly the kind of humorous trolling we wholeheartedly endorse, since it not only spreads good cheer, but more importantly it ensures no man or woman is ever left hanging. [YouTube via Geekosystem via Slacktory]
DISCUSSION
In my son's elementary school, they're not allowed to high five anymore because, according to the principal, "they should keep their hands to themselves."