Web filters block health sites
The infinite subtlety of censorware
A study from the US has shown that Internet filters designed to screen out pornography can end up blocking access to health information Web sites.
The study, carried out by the Kaiser Family Foundation and published on Wednesday in the Journal of the American Medical Association, showed that when Internet filters were set at their most restrictive level, they blocked nearly a quarter of health information sites and half of all sites with advice about safe sex.
The problem is a serious one, says the Kaiser Family Foundation (KFF), because many schools and libraries tend to set Internet filters at their most restrictive level.
American schools receiving federal funds are required by law to have filters on all their computers, although the application of the same law in US libraries was overturned by a federal circuit court earlier this year and is shortly to be reviewed by the US Supreme Court.
Striking a balance between blocking most pornography sites and still accessing health information and safe sex Web pages will depend on the exact set-up of the Internet filtering software, the report said. If not configured carefully, the filters could present a "serious obstacle, especially on issues such as pregnancy, sexually transmitted diseases, and birth control," said Kaiser Family Foundation Vice President Vicky Rideout.
Earlier research has confirmed that the Internet has become a widely used source of information for health information for teenagers, including sexual health. "The Internet has the potential to revolutionise access to health care information and services," said study co-author Dr. Caroline Richardson of the University of Michigan Medical School. "It's important to ensure that filters don't interfere with that potential."
The study, "See No Evil: How Internet Filters Affect the Search for Online Health Information," tested the six most commonly used filters at the "least," "intermediate," and "most" restrictive settings.
The researchers tested the search engines Yahoo, Google, AOL, MSN, Ask Jeeves and Alta Vista. The 3,000 health and 500 pornography sites that came up during these searches were then systematically tested against the six filters most widely used in schools and libraries: 8e6, CyberPatrol, N2H2, SmartFilter, Symantec, and Websense.
The Kaiser study found that running the filters at their highest configuration results in blocking a large percentage of legitimate health sites, while only marginally increasing the amount of pornographic content blocked by the software.
At the least restrictive level, the filters incorrectly block an average of just 1.4 percent of health sites. However, when set at the most restrictive level, filters block 24 percent of health sites. Blocking of sites on sexual health issues such as condoms and safe sex was higher at all levels: from 9 percent at the least restrictive setting to as much as 50 percent of all sites at the most restrictive setting.
The amount of pornographic content blocked was found to increase only marginally, from 87 percent at the least restrictive configuration to 91 percent at the most restrictive level. Significant amounts of information on homosexuality, pregnancy and birth control were also blocked when the filters were set higher. © ENN
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