It is standard on Wikipedia and other sites of this nature to simply disallow proxy servers from posting, I think we should do this for the time being. (I don't think this anymore, see comments below, I think proxy posting is fine)
Still, proxy posting can be useful to assure anonymity, and this might be useful for reviews. People will get paranoid about being located through their IP. How many experts on supernova cores live in Basel, Switzerland, for example? So perhaps one can make it in the future that anonymous proxy stuff is placed posted hidden with a flag, waiting for a manual review. If the post ok, then an admin can unhide it. This shouldn't lead to spamming or trolling, since the spammers won't be able to see the spam.