Google Caching a bit too good?
Website Publisher Sues Google over Caching
Read the above link. Good stuff. Turns out the site Perfect10.com (yes, it's adult stuff,) filed a lawsuit against the internet giant Google for caching full size images that subscribers to Perfect10.com would ordinarily have to pay for.
Personally speaking I am not particularly fond of when search engines "cache" your web site for retrieval later. Granted, when you put up a web site - it's public. Some web sites state in their "Privacy Policy" or "Terms of Agreement" that you either can or cannot save a copy of the web site "for your own personal use" or something to that effect. Most don't. Most webmasters don't even think about it actually.
What you're supposed to do in order to avoid your web site being cached is put either a robots.txt instruction (described here) or a meta tag instruction (described here).
If you don't do what's listed above, every single web page (and image) on your site can and will be cached for retrieval later by a search engine (or two or three or more).
Yikes.