Anonymous proxies are servers that act as intermediaries between the user and the internet, hiding the user’s real IP address and allowing them to bypass network restrictions and access unauthorized websites. The best way to prevent users from visiting unauthorized websites using anonymous proxies is to block the IP address of known anonymous proxies on the firewall or router. This will prevent the user from establishing a connection with the proxy server and accessing the blocked content. Removing the anonymity from the proxy, analyzing IP traffic for proxy requests, or disabling the proxy server on the firewall are not effective ways to prevent future occurrences, as they do not address the root cause of the problem or require more resources and time to implement. References: The 17 Best Proxy Sites to Help You Browse Anonymously; Buy HTTP proxies and Socks5 | Anonymous Proxies; The Best Free Proxy Server List: Tested & Working! (2024).