I think in general this is a good idea but it can really detract from
a nice graphic image to have text written on it.
>Also I think some, perhaps most, grpahics packages allow a file to be
>saved with "meta-information", such as copyright info and creation date,
>as well.
Very true, but easy to change.
>It is my belief, however, that a document on the world-wide-web has been
>made public, and therefore it shouldn't matter whether a web browser
>caches it, or simply views or prints it, or whether a robot references
>the file, or whatever...that the web should mean free sharing of ideas.
Well, printing a book makes it public but does not give you the the
right to pirate it (normally and of course there is "fair use" ...).
>All your copyrighted materials or intellectual property should be behind
>some kind of authentication or security barrier, beyond which a
>traverser agrees to certain terms of non-disclosure before getting
>access to the information. Then if you need to hold someone accountable
>for doing something inappropriate with your sensitive information you
>can go to your logs and say that "You signed this agreement by entering
>this web space...so you can't do that..."
>
>That's my ol' $.02, anyways...
There are some alternatives. For example, there is at least one startup
company creating a digital watermark that is imbedded into the
image itself so it can be recovered even if the image is cropped, etc.
They can even do this for other types of media -- video, sound clips, etc.
Check out "www.digimarc.com".
--phil