is there a way to moderate location field? actually, since it's technically a text field changing it should send profile to moderation, but it doesn't. Would be nice if it does, because people rarely do it for innocent purpose, for example because they moved. 

Usually it's done with malicious purposes (scam or visa-seeking), they put the correct location at registration (knowing their IP address will be checked), then sneakly change it to the more "desirable" US or UK, to get more response.