Once an image is on the web then isn't liking to it entirely fair and not grey at all?
This is known as "deep-linking" and is prohibited (and prevented) by some sites, not liked by many sites, and may infringe copyright (depending on the situation). Some discussion groups have disabled img codes for this reason (and sometimes because of bandwidth). The basic idea is that deep-linking gets you to their intellectual property without them having a shot at selling you something (or whatever) in return for letting you view their intellectual property.
Taken to extreme, any link to a site other than to the home page can be considered as a deep link. A Danish court ruled that any such link is illegal, almost two years ago (
Page not found - Search Engine Watch) although this decision may have been overruled and certainly has had no noticable international effect. As of last September it was definitely legal in Germany but still uncertain in the U.S. (
Deep Linking: Legal Certainty in Germany While Debate Continues in the United States).
{added in edit} The American Library Association has a page of links to articles about deep linking at
Deep Linking.
[This message has been edited by JonF, 04-22-2004]