A number of British mobile networks are blocking the far-right British National Party’s website, it has been revealed.

Following a report by LSE Media Policy Project and Open Rights Group (ORG) on mobile internet censorship, a number of web-users alerted ORG that the BNP’s website is blocked on a variety of mobile networks if child protection filters are active, once again raising the question of the efficacy of online filtering systems.

Though these sites are blocked through child protection systems, ORG argues that often filters such as these are “on by default” and can block too much content through “mistaken categorisations”.

ORG also raise the question of whether internet service providers (ISP’s) should be blocking the website of a political party at all, citing political speech as “the core of the activities protected by freedom of expression rights”.

Upon further investigation of the alleged blocking, Index found it was blocked on Tmobile, Orange and Vodafone. We also noted with particular interest that the site was restricted to over 18s on 02, and subject to a charge of £1 to clarify you were of age to access the controversial political party’s website, and any other age restricted sites. Is this perhaps some kind of “porn tax” from the mobile networks? Why should a customer pay to verify their age?

In her response to the Mobile Censorship report on the LSE Media Policy Project’s blog, Index’s editor Jo Glanville said: “It has long been demonstrated that filtering systems are a blunt tool that censor content beyond the sites that are targeted”.

Glanville added that the criteria for blocking content on mobile phones are “alarmingly opaque” and explains that companies do not inform their customers that their phones “are blocked by default”. Glanville also describes “alarming evidence” detailed in the report, that phone companies failed to act when they were informed that a site had been wrongly blocked.

There is a particular concern that sites which are being blocked by child protection filters cover broader categories than adult sexual content, and that mobile networks are making decisions about what under 18s should be exposed to. ORG argues that the scope of content blocked on the mobile phones of young people should be determined by parents, in a discussion with their children.

“The current panic around protection of children has introduced the mistaken belief that filtering is a solution,” explains Glanville. “ORG and LSE have provided the timely evidence to show that it is, on the contrary damaging.”

It’s not just party political sites which are being blocked by these networks. Users also alerted ORG to a number of “anti-feminism” sites which were being blocked, including www.antimisandry.com, www.exposingfeminism.wordpress.com and www.angryharry.com, are all blocked on o2 and Vodafone, while www.manwomanmyth.com is blocked on Three and Orange. They also detail a number of reports that “lifestyle” sites have been blocked by mobile network providers, along with a number of technology-related news sites and some discussion forums.

And this problem seems to be fairly widespread. A Twitter user today alerted The F Word, a UK feminist site, that access to their website was blocked on o2.

Following their report, ORG and LSE called on mobile networks to offer an “opt in” system for filtering, rather than having to “opt out”, and for further clarity on the source of filtering technology. The report also recommends regular reviews of filtering systems and their efficacy.

Alice Purkiss is an editorial assistant at Index. She tweets at @alicemaypurkiss