Camera prints, film and slides ability to survive thanks to the physical nature of their materials is pretty common. Keeping in mind that photography only began in the 1820's and we may find that digital photography could be even more durable.
I loved reading this story about a DSLR that spend a year at the bottom of a bay. Not only was the diver able to retrieve images, but he also found the owner of the camera and images using a social network.
A bit more disconcerting is this story of a woman who finds a family photo in Ikea that she posted to her blog. Ikea bought the image from a stock photography company. I was unable to find a follow-up to this story. Most likely the stock photography company paid their base rate for a stock photo if there's no copyright infringement.
My two conclusions:
- Make sure you erase that SD card really well before you sell off an old camera.
- Before posting images to the web consider adding a digital watermark like Digimarc for Images and copyrighting them. If your stolen photos are found and have your copyright you could do better than a base rate for stock photos.