8e6 Technologies has released ProxyBlocker, a gateway appliance designed to stop employees or students using web proxies to bypass censorware.

"The ability to create a web proxy has gone open source, with toolkits like PHProxy available from SourceForge and other places that give you a way to set up a web page and turn it into a proxy server," said Gary Ulaner, director of product management at 8e6.

He said some users are also using generally available anonymous proxy sites to circumvent their organisation's web filters.

According to 8e6, the ProxyBlocker appliance can identify web proxies through pattern-recognition technologies that don't rely on the URL alone. This technology is also available in 8e6's appliance line for URL, instant messaging and peer-to-peer file filtering.

Ulaner said ProxyBlocker is available as a stand-alone product to organisations that may have already installed competitors' web-filtering products, which may not be capable of proxy-blocking.

ProxyBlocker starts at $2,500 for software, plus $1,500 to $4,000 for hardware.