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April 8, 1999
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Sticks and Stones Can Hurt, but Bad Words Pay

Makers of Web Filters Fight Over Carefully Compiled, Closely Held Lists of Blocked Words


D ISPUTES over the content of words and Web sites are nothing new. These days, they usually involve people fighting to filter what children see on the Web, or other people fighting for their right to speak, print or send via computer any words they like. Now an Internet filtering company has added a new twist to the battle over what is banned: it is accusing another company of stealing its list of banned words and Web sites.

The filter companies involved are Cybersitter and Clickchoice; ICQ, an instant messaging service on the Web that once recommended the Clickchoice filter to its users, has also been swept into the fray. The dispute has illustrated how difficult it is for a filtering company to keep its lists of banned words secret and added fuel to the debate over whether such secrecy is warranted.

Officials for Cybersitter accuse Clickchoice of using Cybersitter's proprietary list of filtered words as the basis for its own filtering software, which it formerly offered online. Clickchoice denies that. But Cybersitter is still considering a lawsuit, said Marc Kanter, vice president for marketing at Cybersitter's manufacturer, Solid Oak Software, based in Santa Barbara, Calif.

The conflict is rooted in the difficulty of setting up a filter that blocks what is intended but does not block innocuous sites or references that just happen to include, say, the word breast. When a site is requested through a Web browser or search engine, most filtering software checks the requested Web address against a list of taboo sites. Some software, like Cybersitter's, also reads words that have been typed into search engines and checks them against a list of banned words. If a match is found, the search engine won't display links to the offending sites.

In the case of chat-room filters, sometimes typed words -- as well as links to Web sites -- are blocked.

Devising a list of sites and words to ban involves many tricky decisions. Some filters are based on specially devised formulas that catch combinations of words and phrases; others include Web sites that may not include words like sex or naked, yet are still deemed to be pornographic. Most companies consider the lists they have compiled to be precious trade secrets, hidden behind encryption and released to no one. Even customers who download the software onto their computers have no access to the lists that control what sites and words are blocked; they can find out what is included only by searching for specific terms or pages to find out if they are filtered out.

"If we published the list, we would be shooting ourselves in the foot and giving ammunition to competitors," said Theresa Marcroft, a marketing director for SurfWatch, a leading Internet filter.

The dispute over Cybersitter's list began last month when an ICQ user discovered that ICQ was directing customers who wanted a filter to a site called There, users could download two Clickchoice filters that were designed to work with ICQ. One of the filters blocked the appearance of some words that many people do not consider inappropriate for children, like words about gay rights. Some ICQ users were appalled that ICQ was promoting the Clickchoice software as its filters of choice, and a few online news organizations reported the complaints.

The flap dissipated within a few days, as soon as ICQ stopped linking its customers to the Clickchoice site. An ICQ spokeswoman attributed the link to Clickchoice to an "internal problem" and said ICQ was not in the business of endorsing one filter company over another.

A new problem emerged when Cybersitter received a call from a reporter for CNET's who had reported that one of the Clickchoice filters worked suspiciously like Cybersitter's. The reporter sent Cybersitter a copy of Clickchoice's list of banned words, which she had received from Peacefire, a youth group opposed to Internet filters. The group had downloaded the Clickchoice software and viewed its list, which unlike those in most filters was not encrypted.

That list of banned words and sites matched the list that Cybersitter had used in creating its software two years ago, said Kanter, of Cybersitter.

He said it had become unquestionably clear that Clickchoice had used the Cybersitter list to create its own software.

"This was blatant," Kanter said. "It's just amazing to us."

In an interview, Joseph Provissiero Jr., vice president of marketing and sales at the Clickchoice Company, based in Atlanta, apologized for offending anyone with the choice of words for the company's filter but contended that Clickchoice had "not done anything wrong."

Nevertheless, Clickchoice no longer offers the ICQ filter. In fact, Provissiero said, Clickchoice is not in the business of creating filtering software at all. What Clickchoice is developing is still secret, he added.

Clickchoice's Web site is blank except for this statement: "The purpose for which this site was originally created is no longer valid. Site is now being revised."

Hackers may have also played a role in the dispute. Kanter, of Cybersitter, said that Clickchoice had received a copy of its banned words after Cybersitter's list was decoded two years ago by Peacefire.

In 1997, Bennett Haselton, a Vanderbilt University graduate student who started Peacefire, wrote a program that could decode Cybersitter's filter. Once a person ran the decoder, a text-based list of Cybersitter's banned words and taboo sites would appear. Soon Cybersitter's list was being posted on Web sites around the world.

Kanter said it was obvious that Clickchoice had got one of those decrypted lists and used it as the basis of its ICQ software. For example, he said, he found the words "Don't buy Cybersitter" in Clickchoice's list -- words that Cybersitter added to its secret list years ago, when an anti-filtering campaign with the slogan "Don't buy Cybersitter" was raging online.

Provissiero denies that Clickchoice's list was once Cybersitter's.

"There were a variety of sources that were used when the list was compiled," he said.

Other filtering companies, like Surf Watch, have also fallen prey to hackers. Both Surf Watch and Cybersitter now use stronger encryption to lock up their lists. But it seems that doing so only increases the decoders' appetite for the keys. Newsgroups are peppered with conversations among children who want to figure out how to unblock their parents' blocking software and with advice being passed among people who want to expose exactly which sites a filtering company filters.   

Those opposed to the use of Internet filters in public libraries and schools are disturbed by the secrecy surrounding blocking software. In a recent court case involving the library board in Loudoun County, Va., lawyers for the residents opposed to filters asked for the right to see what words and Web sites would be banned. X-Stop, the software company hired by the library, refused to turn over its list, calling it a trade secret.

That refusal became part of the plaintiffs' case against the use of filters. The library board had argued that installing filtering software was no different from librarians' making decisions about what books to stock on the shelves. But Bob Corn-Revere, a lawyer arguing against the library board, pointed out that when librarians made decisions about books, they knew exactly what they were deciding to include or exclude.

"But if they were using Internet filters," Corn-Revere said, "how would they know?"

The American Civil Liberties Union would much prefer that the lists be made public, said Ann Beeson, an A.C.L.U. lawyer who specializes in Internet censorship. She said she knew of only one filter -- called Net Nanny -- that gave its customers the option of viewing its list of banned sites and words. The rest of the filtering companies keep their lists closely guarded.

Such secrecy, Ms. Beeson said, "prevents the consumer from knowing what in the world they are buying when they buy these products." Besides, she added, once lists are exposed, it becomes clear that claims about the importance of protecting trade secrets are "a lot of smoke and mirrors." Some of them consist of little more than a batch of profanities and descriptions of sex, she said.

Officials for filtering companies vigorously disagree. They say building these lists is arduous and time-consuming.

Cyber Patrol, for example, employs 10 people to spend eight hours a day at the company's headquarters in Framingham, Mass., reviewing Web sites culled by online robots called Web crawlers that were built by Cyber Patrol to search for potentially offensive material. Those researchers then categorize the Web sites into groups like "violence/profanity" and "gross depictions." As with other Internet filters, customers cannot see the sites that are grouped under each category, but they can decide which categories they want to be blocked.

"An intellectual process has been applied here," said Susan J. Getgood, Cyber Patrol's vice president of marketing. "The fact of that work makes the list our intellectual property."

Interestingly enough, Cyber Patrol has also created a list of sites that it says are not only safe for children but are also designed to be educational and fun. But the company isn't taking any pains to protect that list as its intellectual property: the list is not protected by encryption or even sold. It's free on the Web, for anyone to view.

 See also: Anti-Defamation League's Crusade against Internet Freedom

Anti-Censorship Proxy

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© Focal Point 1999 e-mail:  write to David Irving