Although I have not posted as much art to Artsonia since I have been at the high school level (mostly for lack of time), let me just say that over the years I have had two students approached by publishers (contacting them through me) to use their artwork in textbooks as examples. The students (and parents) were excited and they were paid for the use. So....another benefit!
Marianne in Ohio
Subject: RE: artsonia. used to be "end of year art
From: marcia <firstname.lastname@example.org>
Date: Mon, 26 May 2008 01:57:57 -0700 (PDT)
However, if someone is devious enough to steal someone
else's artwork to submit in their portfolio, I doubt a
copyright would stop them from using it. I think the
benefits outweigh the potential risk. Anytime you
post something on the internet there's a possibility
of someone stealing it.