Open Rights Group Open Rights Group

Frequently Asked Questions

Here are the answers to some questions we've been asked.

If your question isn't answered here feel free to contact us.

Results and reports

Why is my site listed as blocked?

Our probes tried to visit your site via each mobile and home-broadband network we monitor, but instead of returning the page as normal, some or all of the ISPs sent a page telling us their filters have blocked the site.

Each test line is configured with its default level of filtering. The results you're seeing are what the Government would like each ISP to nudge their customers into using.

What do the results mean?

  • OK - our probe got a good response from the site that didn't resemble this ISP's "we've blocked this site" page.
  • BLOCKED - our probe got the response it expects to see when this ISP's filters have blocked a site.
  • ERROR - our probe got a bad response from the site. Resubmitting the site might work.
  • TIMEOUT - the site hasn't responded via this ISP yet, or took too long to respond so our probe gave up. Refreshing the results might work. (See the next question too).

Why have all or most of the tests timed out?

If you're seeing a lot of timeouts it could be that the site you're testing uses TLS with Perfect Forward Secrecy. This increases the length of time between requesting the site and its content being returned. We're looking into tweaking our probes to detect this and allow a little longer for the test.

BT's blocking is a bit of a blunt instrument - if you try to connect to a site that is blocked using HTTPS, you'll get a timeout. The proxy server that their DNS hijacking directs your request to doesn't respond on port 443.

If you don’t list my site as blocked, does that mean it isn’t blocked?

Unfortunately, no. At the moment, we've chosen the “default” choice for filters on ISP networks. Some ISPs allow account-holders to filter much, much more. Hopefully we will be able to test for stricter filters in the future. We also can’t test all filters everywhere, as many people are on private networks. We hope to get more information about filters in schools, workplaces, libraries and on public wifi networks in the future.

I [can / can't] access a site but my results say it's [blocked / OK]. Why?

The filtering settings on your network might be different to those we've configured on our test lines. Here are some other possible explanations :

  • We're not yet covering public wifi hotspots, business networks, or most niche broadband providers.
  • If you're on a mobile network other than those we monitor they might have special arrangements for filtering.
  • If you are running a software product that provides filtering, such as an anti-virus tool or a security suite, this might be blocking sites.
  • If you are using a third-party DNS-based filtering system, such as OpenDNS, this might be responsible.
  • Filtering behaviour might differ between types of mobile connection. Our mobile broadband test-lines use contract data-only SIMs.
  • Some websites block access by geographic location or other criteria. Sometimes it's not clear whether this is happening in the network or at their server.

Why are there no results for my site on network X? Why aren't the results for my site getting refreshed on network X?

If we're monitoring that network then our probe might be offline or under heavy load. Please try again later.

Filtering, blocking and censorship

Are sites blocked in the UK for reasons other than adult-content filters?

Yes. The government estate (schools and hospitals, for instance) blocks what they believe to be "extremist material." UK courts have ordered blocks on some websites that enable copyright infringement. A handful of URLs are blocked by members of the Internet Watch Foundation for containing child abuse material.

What filtering was enabled on your test lines when they were installed?

EE, O2, TalkTalk and Vodafone all came with their default "adult content" filters enabled by default. The following ISPs provided no filtering by default: 3, Andrews & Arnold, BT Broadband, Plusnet, Sky Broadband and Virgin Media.

What results has Blocked found so far?

Before we launched the site we tested the top 100,000 sites (as ranked by Alexa at the time) on each of the networks we monitor. We found that just under 19% of these were blocked on at least one network.

Where can I learn more about UK web blocking?

There's a detailed information page on Wikipedia. This page also has a list of site categories blocked by different ISPs in different circumstances.

How it works

What networks are you monitoring?

We have test lines from 3, Andrews & Arnold, BT Broadband, Everything Everywhere, O2, Plusnet, Sky Broadband, TalkTalk, Virgin Media and Vodafone.

Why did you pick these networks?

Andrews & Arnold sponsor this project. They also offer only unfiltered connections so they are a yardstick against which to compare other providers.

We chose BT Broadband, Plusnet, Sky Broadband, TalkTalk and Virgin Media because these are the ISPs the Government has pressured into agreeing to install “active choice” adult-content filters for new and existing customers. Together they provide over 90% of UK home broadband connections (according to the thinkbroadband UK Broadband Factsheet, Q1 2014, P3).

We chose 3, EE, O2 and Vodafone because these are the only licensed Mobile Network Operators (MNOs) in the UK. All have default-on filters. Other companies such as GiffGaff, Virgin Mobile and Tesco Mobile are known as Mobile Virtual Network Operators, or MVNOs. The MVNOs all use the infrastructure of one of the four MNOs to provide their service. As part of this, we believe they also inherit the parent service's filtering infrastructure, though they can choose whether to make this available to their customers. So MVNOs either have no filtering or the same filtering as one of the MNOs. That means we can cover the entire UK mobile market by monitoring just the four MNOs. Wikipedia has a list of UK MVNOs and the MNO that provides service to each.

What filtering settings are enabled on ORG's home broadband test lines?

Andrews & Arnold do not offer filtering so we couldn't enable any.

BT Broadband filtering is set to "light", which they say blocks the following categories:

  • Pornography
  • Obscene and Tasteless
  • Hate and Self-harm
  • Drugs
  • Alcohol and Tobacco
  • Dating

PlusNet do not offer network-level filtering so we couldn't enable any. We have enabled "Safe Surf" and "Broadband Firewall" though.

Sky Broadband filtering is set to "13" which they say is "suitable for teenagers and above". They say this blocks the following categories:

  • Cyber bullying
  • Pornography and adult
  • Suicide and self harm
  • Weapons, violence, gore & hate
  • Anonymizers, filesharing & hacking
  • Drugs and criminal skills
  • Dating
  • Phishing, malware & spyware 

TalkTalk KidSafe is enabled. We have also enabled "Virus Alerts". The categories they say KidSafe blocks are:

  • Dating
  • Drugs, Alcohol and Tobacco 
  • Gambling 
  • Pornography 
  • Suicide and Self-Harm 
  • Weapons and Violence

Virgin Media's parental controls are set to "on".

What filtering settings are enabled on ORG's mobile broadband test lines?

We asked 3 to enable adult-content filtering. They said they'd try but it might not work. 3 switched off default filtering for contract data-SIMs in March 2011.

Everything Everywhere's Content Lock product is enabled.

O2 block "18+ rated websites" by default. This is enabled.

Vodafone Content Control is enabled.

How do ORG's probes determine whether a site is blocked?

The probes look for the messages that ISPs return instead of the page you asked for when they've blocked a site. If a probe doesn't see a "page blocked" message, and there was no error, then it assumes what was returned is the normal version of the site and reports "OK". This might mean we're missing some forms of censorship, or might start to do so if an ISP changes its "blocked page" message. If you think that's happening please contact us and let us know.

How often are sites checked?

User submitted sites are checked straight away and the results are normally available within a few seconds.

We send user-submitted URLs, and the Alexa 100k top-ranked sites, to a re-check queue at a rate of 4800 per day (in last-checked order). User-submitted URLs must be more than seven days old to be requeued. With the current database contents, this means we re-check the entire list every 20 days. Re-check URLs go to a different queue from real-time user submissions so they don't get in the way of your results being returned.

Getting involved

Who made this?

Please see the credits page.

How can I help?

See the get involved page for practical ways you can help, such as analysis, coding, campaigning and joining ORG.

Can I run my own probe?

We have plans to allow this in future. Right now we're developing a few different probes, including an Android app, a GNU/Linux command-liine probe and integration with ooniprobe. We'd also like to build a browser extension. If you want to help with any of these projects please take a look at our get involved page.

Can I try this in my country?

Yes. our code is Free software and we would be very willing to help you set up your own version, or collaborate on a central repository. Ooni from Tor is also Free software and we are working on integrating it with our system. Please contact us if you want to explore further.

Can I get hold of the raw data?

Yes, you can download a snapshot of the data from 29 June 2014, or a nightly update, licenced as described on our licence page.