until they figure out that it is a proxy being used to bypass their firewall filter, and they block the proxy address. They will figure this out when he visits the proxy address more than 25 times a day. If they are truly corp paranoids, they will have blocked most publically available proxy servers like those found on [link|http://www.astalavista.com|[link|http://www.astalavista.com|http://www.astalavista.com]]

P.S. Beware of the "Internet Use" policy. They may have a policy against using proxy servers to bypass their Firewall Filters. Most Brain-Damaged Corps have a moronic policy like that and breaking it can get you terminated.