Ed-
The fact is, anyone can contribute to Wikipedia. Just create a handle and start typing. People who don't want their contributions tracked are subverting the WikiWiki principle and should not be helped. (If you're contributing at the risk of your life, contact ME and I'll set up something safe for you through the underground.)
I have changed the IP block messages for anonymous proxies accordingly. See http://en.wikipedia.org/wiki/Special:Ipblocklist
Regards,
Erik