LONDON — The parental filters of U.K. ISPs are blocking 20 percent of the 100,000 most-visited websites on broadband and mobile phone, according to the Open Rights Group.

Even XBIZ.com apparently is being blocked by six U.K. ISPs, as seen by a new tool released by the group. So is SFW sister site XBIZNewswire.com.

The Open Rights Group embedded tool runs checks on all the major broadband and mobile filters of U.K. ISPs — 3, Andrews & Arnold, BT, Everything Everywhere, O2, Plusnet, Sky Broadband, TalkTalk, Virgin Media and Vodafone — and allows users to query which sites are blocked.

U.K. ISPs have automatically been imposing filters on new customers since the beginning of the year unless specifically asked not to do so. Existing customers are next in the new policy under Prime Minister David Cameron.

Open Rights Group officials said that the ISPs, in many cases, are blocking sites that are not harmful to children.

“Sometimes, they are blocked by mistake,” the group said. Sometimes, they are blocked deliberately. For example, many blogs and forums are blocked by default.”

The group, which released its findings today, said that the problem of over-blocking is not going away

“Different ISPs are blocking different sites and the result is that many people, from businesses to bloggers, are being affected because people can’t access their websites,” the group said. “We’ve found that there is a lack of information about how to get sites unblocked.”

Open Rights Group officials said they’ve created a page devoted to personal stories about blockage and welcome comments.

xbiz