http://i60.tinypic.com/2mc9kr5.png

Use a free service like Black Box Proxy Block to check if an IP address is associated with an open proxy server.

Black Box Proxy Block: http://www.shroomery.org/ythan/proxyblock.php

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Guys, check this: https://www.blocked.com/index.php

- https://perishablepress.com/block-tough-proxies/

- https://perishablepress.com/how-to-block-proxy-servers-via-htaccess/