A few days ago a message was posted about the ease of gathering
images from web pages. While it is very easy to download an image
from a web page, the image may not be free to take.

Artists are particularly aware of this issue. Common methods of
protecting images include watermarks on the image, copyright
statements on the page or image, and scanning at a lower resolution
to discourage theft.

A very good discussion of copyright is from
December 1996,  Copyright, Educational Fair Use, and the
Information  Superhighway, by  Karl M. Gauby,
Arizona State University, Educational
Leadership and Policy Studies
http://tikkun.ed.asu.edu/epsl/briefs/brief23.htm

Before you download someone else's images please read this article.
The American Library Association and the U.S Government both have a
wealth of information about copyright and fair use. All images posted
to a web page are copyrighted whether it is explicitly stated or not.
 thanks