[Clipart] Help needed for explaining Why PD?

[Bryce Harrington]

Would someone mind writing a nice explanation for "Why OCAL requires
contributions be Public Domain?" for our FAQ?  In looking through the
site it looks like we don't yet have a good explanation for this.
Several people wrote some very good explanations this last week, so I
bet a good write-up could be made by just summarizing those comments.

Please post it to the Wiki at http://openclipart.org/cgi-bin/wiki.pl?FAQ
and we'll copy it into the main FAQ when it's good to go.

Bryce