The entire world was on edge following the events of September 11, 2001. A terrorist attack on New York left the United States stunned, and the internet was obsessed with the event for years to come. Innocent tourist Péter Guzli had previously travelled from his native Hungary to check out the famous World Trade Center and take in views from the observation deck.
Thinking he'd make friends laugh, Guzli crudely photoshopped in a plane behind him and emailed the image to pals. No, this wasn't some sick joke played by Péter to mock the tragedy. Note the use of the word previously in the prior paragraph; the pic was actually taken in 1997. The internet just went crazy about it post-9/11.
Guzli became known as 'Tourist Guy', and people genuinely believed he had been standing on the deck when one of the planes smashed into the tower. He hadn't, and he was nowhere near New York when terrorists changed the world.