Government-led attempts to impose porn-blockers on new broadband connections has also blocked sex education websites, advice for people suffering domestic abuse and forums for people struggling with addiction… to porn.

The filters are designed to protect young people and families from ""stumbling across hardcore legal pornography", Prime Minister David Cameron said last week.

But report by the BBC's Newsnight showed that the four big ISPs which have rolled out their filters have all ended up blocking access to legitimate, mainstream sites.

BT's filter - which launched this week and forces users to opt in or out when they turn on their service - is one of the main offenders identified in the report.

Among the sites currently blocked by BT include Reducing The Risk, a site designed to help victims of domestic abuse. A local domestic abuse hotline has also been blocked in Doncaster, while Sexual Health Scotland has also effectively been taken offline by the filter.

In a wider test, TalkTalk was found to have blocked sites including Bish UK, a sex-education site, and a women's rape centre in Edinburgh, while leaving 7% of porn websites tested by Newsnight open.

Sky's filter was found to have blocked about 99% of porn sites, but also blocked six sites set up specifically to help people addicted to pornography.

A £25 million advertising campaign will begin in 2014, funded by ISPs, to try and explain the filters. Meanwhile the prime minister has said he plans to extend online blocks to "extremist" sites - further worrying campaigners for online freedom that the government has too much control over the web.

All of the companies identified by the Beeb said that their filters would improve over time:

TalkTalk: "Sadly there is no silver bullet when it comes to internet safety and we have always been clear that no solution can ever be 100%. We continue to develop HomeSafe and welcome feedback to help us continually improve the service."

Sky: "We know that no one single technology currently provides all the answers. That's why we have a quick and easy way for misclassified sites to be unblocked. Any Sky home has the ability to fully customise their filters."

BT: "Categorisations are constantly updated to keep pace with changing content on the internet and we will investigate any concerns and make changes as necessary. BT Parental Controls can be customised to suit each individual family's needs."


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  • Fingerprint Gel

    The Japanese government counter-terrorism practice of <a href="http://www.reuters.com/article/2007/11/20/us-japan-fingerprinting-idUST23858020071120" target="_hplink">fingerprinting foreigners who enter the country</a> may have inspired Doctor Tsutomu Matsumoto to invent "fingerprinting gels", a way of <a href="http://cryptome.org/gummy.htm" target="_hplink">faking fingerprints for scanners</a>. <a href="http://www.dansdata.com/uareu.htm" target="_hplink">Learn how</a> to make your own here.

  • White Noise Generator

    Worried someone around you is <a href="http://articles.businessinsider.com/2011-07-28/strategy/29998051_1_bank-employee-consent-conversation" target="_hplink">secretly recording everything you do?</a> No fear! There's a relatively low-tech way to defeat such snoops, via white-noise-producing <a href="http://www.amazon.com/Productive-Home-Security-Prducts-Jammer/dp/B002PJ7PYS" target="_hplink">audio jammers</a>. These tiny devices use white noise to blur the sound picked up by hidden microphones and other surreptitious recording devices.

  • LED-Lined Hat

    Hidden cameras got you down? Blind them all with a simple baseball cap lined with infrared LEDs. <a href="http://creator.wonderhowto.com/amiehold/" target="_hplink">Amie, a hacker on WonderHowTo</a>, shows the world <a href="http://mods-n-hacks.wonderhowto.com/how-to/make-infrared-mask-hide-your-face-from-cameras-201280/#" target="_hplink">how to make one</a>, while <a href="http://translate.google.com/translate?u=http%3A%2F%2Fwww.oberwelt.de%2Fprojects%2F2008%2FFilo%2520art.htm&langpair=de%7Cen&hl=en&ie=UTF8" target="_hplink">this German art exhibition</a> lays out how these ingenious devices work.

  • Bug Detector

    These receivers reveal the telltale electronic crackle of hidden mics and cameras. Strangely enough, they were around long before "surveillance culture" became a <a href="http://digitalcommons.law.yale.edu/ylsspps_papers/64/" target="_hplink">common phrase</a>. Today they're sold in all sorts of <a href="http://www.gadget-playground.com/bug-detection.html" target="_hplink">shops for surveillance paranoids</a>.

  • Camera Map

    Sometimes hiding your face isn't enough; sometimes you don't want to be seen at all. For those days, there's camera maps. The <a href="http://www.mediaeater.com/cameras/locations.html " target="_hplink">NYC Surveillance Camera Project</a> in the US is currently working to document the location of and working status of every security camera in New York City. <a href="http://bigbrotheriswatching.co.uk/Anpr_Camera_Locations.html" target="_blank">A similar project</a> is also in progress in the UK.

  • Dazzle Camouflage

    Credit to artist <a href="http://ahprojects.com/" target="_hplink">Adam Harvey</a> for this one. Inspired by the <a href="http://www.bobolinkbooks.com/Camoupedia/DazzleCamouflage.html" target="_hplink">"dazzle camouflage" </a>used on submarines and warships during World War I, he designed a series of face paint principles meant to fool the facial recognition schemas of security cameras. Check out <a href="http://dismagazine.com/dystopia/evolved-lifestyles/8115/anti-surveillance-how-to-hide-from-machines/ " target="_hplink">The Perilous Glamour of Life Under Surveillance</a> for some tips on designing your own camera-fooling face paint.

  • Throwaway Phones

    Disposable mobile phones <a href="http://www.amazon.co.uk/Pre-Pay-Mobile-Phones-Communication/s?ie=UTF8&page=1&rh=n%3A10394961" target="_blank">are more expensive than you think</a>, but they don't require personal information when you sign up.

  • RFID-Blocking Wallet

    Radio-Frequency Identification (RFID) chips are now <a href="http://electronics.howstuffworks.com/gadgets/high-tech-gadgets/rfid.htm" target="_hplink">regularly implanted</a> in passports, ID cards, credit cards and travel papers. These tiny chips make machine-reading your documents easier -- but could also let anyone with the right type of scanner <a href="http://articles.cnn.com/2006-07-10/tech/rfid_1_rfid-industry-rfid-journal-rfid-chips?_s=PM:TECH " target="_hplink">scrape your information <em>and</em> track your whereabouts</a>. Luckily, gadget geeks have come to the rescue again, this time with<a href="http://www.thinkgeek.com/product/8cdd/" target="_hplink"> RFID-blocking wallets</a>. These wallets create a Faraday cage around your items, keeping their data secure until you take them out to be scanned where they're supposed to be scanned. Destroying the chip is simpler: <a href="http://www.instructables.com/id/How-to-blockkill-RFID-chips/" target="_hplink">just nuke it in the microwave for five seconds</a>. Of course, whatever you're microwaving might <a href="http://www.youtube.com/watch?v=4_5UYcyO3Pg" target="_hplink">burst into flames</a> first...

  • Use Skype

    The progress of the government's so-called 'Snooper's Charter' is currently stalled in Parliament, but using Skype may be a way to avoid officials tracking your phone calls. <a href="http://www.techweekeurope.co.uk/comment/how-to-avoid-gchq-snooping-use-skype-71410">Tech Week Europe suggests that Skype users have less cause to be worried about their data</a> being intercepted. The reasons are pretty technical, and any system is fallible, but it may be worth looking into.