For $31, a British man bought a Nikon Coolpix camera off eBay and found that the memory stick contained highly secret MI6 anti-terrorism information. In the files were names of suspected Al Qaeda militants and photos of weapons those terrorists have as well as details on an high-encryption MI6 computer system used to keep track of intelligence details. The files were discovered when he downloaded his pics after a vacation.
No, I'm not making this up. Here's MSNBC's story on the breach.