Fake images are everywhere. You know that. You know that Kate Upton doesn't really look like this (spoiler: she has pores just like you). You know that your burger isn't going to look like this. And all this wouldn't be a big deal except that fake images can totally alter our memories. If you show people a doctored image of themselves riding in a balloon as a kid - a lot of them will remember it happening. If you show people ad copy of someone else shaking hands with Bugs Bunny at Disneyland, and then send them to Disneyland, a large portion of them will remember shaking hands with Bugs Bunny. Which is impossible because, as a Warner Brothers character, Bugs has never set foot in Disneyland in his whole cartoon life.
Just a few notable images that are totally fake include an iconic picture of Abraham Lincoln, the picture of Romney's kids spelling out money, any picture of a shark during a storm ever, and the famous picture of John Kerry and Jane Fonda, the list goes on.