Thanks for your response on my talk page The identity of the anon editor is this case is pretty obvious since the author of the vanity press Rydberg books posts from those same IPs under his real name on a number of Internet fora invariably promoting Rydberg and his books He s simply trying to drum up more sales by preventing any balanced assessment of Rydberg s work in the Wikipedia article Before I try to involve more editors I d like to know whether it s permissible to look outside Wikipedia to determine the identity of an anonymous troublemaker like this