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CYBERsitter Examined

Why CYBERsitter is the most heavily criticized blocking program in the industry

With the events that have taken place since July 1996 -- when CYBERsitter first threatened legal action against two reporters who decoded the program's list of blocked Web sites -- CYBERsitter has very fewer defenders on either side of the blocking software debate. Supporters of blocking software have distanced themselves from the company, while even opponents of blocking software concede that CYBERsitter's actions are not representative of the entire industry:

  • In July 1996, reporters Brock Meeks and Declan McCullagh published "Keys to the Kingdom", an article about the blocking policies of several filtering companies, including CYBERsitter. The article revealed that CYBERsitter maintained a policy of blocking pages which advocated equal rights for gays and lesbians, such as N.O.W..
  • In August 1996, CYBERsitter president Brian Milburn sent the reporters a letter claiming copyright violations and threatening FBI criminal prosecution, because the article revealed some of the words and phrases blocked by CYBERsitter.
  • In December 1996, CYBERsitter added to their list of pornographic sites in response to this page being published.
  • On the same day in December, Mr. Milburn sent a letter to Peacefire's ISP threatening to block all sites hosted by our ISP if Peacefire were not removed. Mr. Milburn's letter to Peacefire, which also threatened legal action, stated, "Beginning Monday, we will be contacting customers of MEDIA3 (if any) to let them know who is responsible and why 900,000 Internet subscribers no longer will have access to their sites."
  • In January, The Ethical Spectacle mirrored our CYBERsitter page to protest it being blocked by CYBERsitter; CYBERsitter discovered the mirror site and added to their blocked site list, as reported in the New York Times later that month.
  • In June 1997, reporters at Wired and PC World confirmed that CYBERsitter had re-written their installation program so that when you tried to install CYBERsitter, it would scan your browser's cache to check whether you had ever visited the Peacefire Web site -- and if you had, the software would generate a fake error message and refuse to install.
  • In January 1998, CYBERsitter sent a mail-bomb of about 500 junk messages to a lady in Massachusetts who wrote to them to complain about their blocking policies. Her postmaster was monitoring the incoming mail traffic at the time of the mail-bombing attack and notified network security authorities at MCI. PC World and C-Net covered the story of the mail-bombing attack.

Sites blocked by CYBERsitter

Due to the explosion of news articles about CYBERsitter's legal threats and abusive behavior (even towards journalists writing about the company), much less attention has been paid to the issue of what sites are actually blocked by their software.

The latest versions of CYBERsitter rely almost entirely on keyword filtering, not on a "list of sites" built in to the program. There is a built in list of sites, but it only contains a few well-known URL's like The filters in the latest versions of CYBERsitter mostly contain a list of words and phrases; CYBERsitter blocks any page which contains a word or phrase on this list.

Prior to CYBERsitter 99, CYBERsitter wouldn't actually block a page because the page contained a "bad phrase", it would just display the page with the word deleted. This led to some amusing anecdotes about sentences whose meanings changed when viewed through CYBERsitter, e.g. "The Catholic Church opposes homosexual marriage" would be rendered as, "The Catholic Church opposes marriage". But starting with CYBERsitter 99, CYBERsitter would block any page that contained one of the "bad phrases".

Our Amnesty Intercepted report included some examples of documents on the Amnesty International home page which were blocked by CYBERsitter's phrase filter. One page was filtered because it contained the sentence "Reports of shootings in Irian Jaya bring to at least 21 the number of people in Indonesia and East Timor killed or wounded..." and CYBERsitter filtered the phrase "least 21". The report linked to a page on CYBERsitter's Web site which stated:

"One of CYBERsitter's most unique features is its state of the art phrase filtering function. Rather than block single words or pre-defined phrases, CYBERsitter actually looks at how the word or phrase is used in context. Not only does this provide an excellent blocking method for objectionable text, but it eliminates the possibility that words with double meanings will be inadvertently blocked."
but this page was deleted from CYBERsitter's Web site after the report was released.

Prior to the release of CYBERsitter 99, CYBERsitter still relied on its built-in list of blocked Web sites, and the contents of those lists were the subject of much controversy. Peacefire still maintains a list of some sites that we found to be blocked, including non-profit organizations and educational sites. Some of these (e.g. Mother Jones) were unblocked after the owners complained.

How to contact CYBERsitter

You can contact Solid Oak Software, the makers of CYBERsitter, at (800) 388-2761, or visit their contact information page at