http://www.globetechnology.com/servl...ry/Technology/ 
It mentions Google, but all search engines work on a similar system. All search engines cache meta keywords from a site, and text to improve matching, to also show the search keywords in context, to help the user decide the best hits. They particularly don't like the imaging search of Google/Yahoo.
This would also affect the Wayback machine at
www.archive.org as well.
Seems crazy to me... Search engines display copyright material with obvious references to the owner's original material, and it doesn't try and claim ownership. However, you could technically argue that it profits from displaying copyrighted material...