1. Everybody loves a good fake picture.
2. Of course, picture hoaxes were popular long before the internet.
3. But the internet's taken them to a whole new level.
4. Pictures about shocking and frightening events get shared a lot.
5. And massive animals always go down well.
6. You can Photoshop pictures to make the world seem more dramatic.
7. Or to make a political point.
8. Or just because it looks cool.
9. Or possibly you wish to defame koalas.
10. Your Photoshopping doesn't even need to be that good. People will still buy it.
11. And the picture doesn't have to be especially plausible.
12. The golden rule: if somewhere has become flooded, you must add sharks.
13. Always sharks.
14. People love sharks.
15. If you can't be bothered Photoshopping something yourself, just take a picture from a TV show.
16. Or a film. A film that even used this as a promotional image.
The Day After Tomorrow, not Hurricane Sandy.
17. In fact, you can normally just find a picture of anything vaguely similar and misattribute it.
Also not Sandy - just a thunderstorm from the year before.
These pictures always make good fake hurricanes. They get wheeled out pretty much any time there's a big one.
They're actually supercell thunderstorms, which look a lot more interesting than real hurricanes.
18. If there's a tear-jerking story that can go alongside the picture, so much the better.
The bike is real, but was abandoned in the 1950s - the story of its owner going off to war is fictional.
19. Or an inspiring message always goes down well.
Really a false-colour composite of images taken over the course of a decade, showing how the distribution of light in India changed over time. Which is actually much cooler than the fake caption.