upside - 6:58 am on Sep 15, 2004 (gmt 0)

There are other environmental variables that can be used for cloaking purposes other than REMOTE_ADDR or HTTP_USER_AGENT such as: HTTP_REFERER, REMOTE_HOST, HTTP_ACCEPT_LANGUAGE, HTTP_COOKIE, and many others. Pay attention to what connections from spiders "look like" in whole not just what their IP is.