age of a shark’s fin that had been Photoshopped into one of the pictures. But even then, we were unable to say that the other image was definitively fake. It used a different shark. Our attempts to find the origin of both shark images kept hitting the barrier of people saying, vaguely, that it was “from Facebook.” We eventually found the originating Facebook poster via a tweet directing us7 to a news site that credited the source. (Both the news report and Facebook posts have since vanished from the Web.) But even that didn’t entirely help, as the page owner’s other photos showed genuine flooding in the same Brigantine, New Jersey, location. He also insisted in replies to friends that the shark pictures were real. (In retrospect, he seemed to be intent mostly on pranking his social circle, rather than hoaxing the entire Internet.) The fact that he was claiming one undoubted fake as real was enough for us to move the other shark image into the “almost certainly fake” category. But we still didn’t know for sure. It wasn’t until the next day, when the fact-checking site Snopes managed to identify the source image8, that we were able to make that call with 100 percent certainty. This was the shark image that was used to create the fake: Photo: Scott the Hobo That may be the main lesson from Sandy: Especially in rapidly developing situations, verification is often less about absolute certainty, and more about judging the level of acceptable plausibility. Be open about your uncertainties, show your work, and make it clear to the reader your estimate of error when you make a call on an image. 46