Viewing Changes to a Digital Image

At DefCon, a conference for computer hackers that takes place in Las Vegas, Neal Krawetz presented a tool that allows the user to see what parts of an image have been edited in later. With this tool, he was able to show that some of the Al-Qaeda videos have been doctored. Not surprising, but interesting.

Please note that despite what the media and pop-culture says, the word "hacker" is not a negative word. A hacker is merely one who tinkers with things. As with similar skills, they can be used for good or bad. A good example would be lock-picking. A locksmith can help you get into your car when you've locked yourself out the same way a thief can break into your car.