Almost one in five websites blocked by filters - Telegraph
A web tool designed to check sites being blocked by ISP filters has been launched

Almost one in five websites are being blocked by overzealous filters, a project has found.

Open Rights Group's Blocked project has created a free checking tool, which returns information on whether a site is being blocked by filters.

To date, the site can checked around 100,000 websites, over 18,000 of which are blocked by one internet service provider (ISP) or more.

Feminist rights blog Sherights was blocked by TalkTalk in April, and another site selling and servicing Porsches was blocked by O2, causing both sites to lose custom and potential advertising revenue, the project said.

Prime Minister David Cameron announced new measures to protect children from accessing online pornography and other potentially harmful content in July 2013.

Mr Cameron said the measures were vital to prevent children “stumbling across hardcore legal pornography”, but concerns have been raised the filters may incorrectly prevent access to sites free from pornographic content.

Jim Killock, executive director of Open Rights Group, said the project was created to examine the impact of web filters.

"Already, our reports are showing that almost one in five websites tested are blocked, and that the problem of overblocking seems much bigger than we thought," he said. "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.

Amendment - an earlier version of this article stated that Order Order, the political blog run by Guido Fawkes, had been blocked by TalkTalk. TalkTalk said the site was not being blocked.