Adobe Tackles Photo Forgeries
Several readers wrote in with a Wired story about the work Adobe is doing to detect photo forgery. They are working with Canon and Reuters (which suffered massive bad publicity last year over a doctored war photo) and a professor from Dartmouth. (Here is Reuters's policy on photo editing.) Adobe plans to produce a suite of photo-authentication tools based on the work of Hany Farid (PDF) for release in 2008.
Besides image manipulation, there is also the problem of staged photographs, as seen in some of the photographs from the recent war in Lebanon. This can't be solved with technology.
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Of course, EXIF contains a lot of information about your camera. However, the data is digital, and can thus be edited. You are free to remove any identifying data from the EXIF headers before you publish your images.