It may not be a good thing, depending on what you try to hide on your computer. 🙂
After seeing it reported elsewhere that Spotlight’s “All Images” search on Leopard really does serve up every image on the system, I decided to give it a try myself and see what turned up. Sure enough, every single piece of spam I’ve received in the last week that included an in-line image (as a MIME attachment) ended up contributing to the show.
In this screenshot, you can clearly see all the images from the spam messages. The on of the woman in the hammock is actually from a spam message, if you can believe that. No idea who she is, but whatever email message that image was sent in got filed as spam.