Carl Bialik from WSJ writes "New Web tools aim to protect surfers by flagging sites that are associated with viruses, spam or other scourges, but they sometimes disagree over whether a site is safe. From the article: 'Scandoo's service sometimes misses the mark in its efforts to flag adult content. On a recent day, it gave a green rating to the web site for Maxim Magazine's U.K. division, even though it contains nudity. It gave a red rating to the magazine's U.S. site, which contains no nudity. After an inquiry from the Online Journal, [executive Dan] Nadir said Scandoo decided to change the rating, reclassifying the U.K. site as red by default. "It was clear that it was misclassified, so we classified it correctly," Mr. Nadir said. A spokesman for Maxim Online said the discrepancy showed Scandoo's technology is "clearly broken."'"