Is Web Filtering possible for a country?

When people ask this question – is it possible to block online pornography in the whole of India, it begs for some discussion. The genesis of this question comes from the fact that we may stop internet porn on our PC or in our homes but how about all the mobile devices, public hotspots, Wifi locations and other private & public places where this may still be easily accessible! This throws up the question – Why not stop this in the country’s Internet infrastructure itself and save us from this fallacy?

Even the honourable Supreme court of India had asked this question to the Government in the Kamlesh Vaswani vs UOI case. The case which is based on a 2013 PIL filed by Mr. Kamlesh Vaswani a lawyer from Indore. In his petition Mr. Vaswani has raised the issue easy availability of Pornography on Internet, while it is prohibited under various acts such as article 67 of the IT Act amended 2008 and Section 13 of the Prevention of Children from Sexual offences (POCSO) Act, 2012. These acts prohibit the storage and transmission of pornographic content via the Internet in India. The government in its response had expressed its  inability to block this at an all India level. They even argued that Pornographic sites are like hydra heads, if you block one then many more will come up. Commenting on this, honourable CJI rightly pointed out –


Law needs to be Faster than Technology


The author who is an Internet Technology expert has in 2014 filed an affidavit in the above case that how this blocking is possible in the whole of India. The technology to do so is readily available and is implemented in many countries world-wide including South Korea (a country with one of the highest Internet usage rates), China, Indonesia, Malaysia, Saudi Arabia etc. The technology that is being recommended is available at a reasonable/low cost and offers negligible or no performance limitations as compared to a normal unblocked Internet. Below are some of the details on this technology, which have been summarized from the said affidavit. You can access the complete contends of the affidavit here – Affidavit filed in court describing the Technology.

Technical Expert Affidavit in Internet Pornography Blocking case – Summary Facts

  1. Techniques available for blocking Internet content can be classified into – IP blocking, DNS tampering/blocking, and proxy-based As of 2008, IP Blocking is being used in 8 countries, DNS Blocking in 5 countries (India as well) and proxy based blocking in 16.
  2. Out of these DNS blocking is the most efficient and cost effective technique, wherein only the required pornographic sites get blocked. This when combined with selective traffic monitoring of suspected IP addresses leads to a very effective blocking infrastructure.
  3. DNS Server is like a Phone book of the Internet. For example, e.g. when you visit in a browser, your computer contacts a DNS server to retrieve the website’s IP (Internet Protocol) address of Without DNS servers, the Internet would shut down very quickly. Currently all DNS servers are being maintained by various Internet Service Providers (ISPs) in India e.g. top 4 are BSNL, Bharti Airtel, Vodafone & Reliance. It is an important control point for blocking of websites.
  4. Websites for blocking are identified via multiple means –
    1. Citizens provide info about such sites (e.g. Petitioner supplied list of 850 porn sites to Ms. Pinki Anand, ASG),
    2. Web scanning software search for pornographic sites.
    3. Databases supplied by various vendors ( e.g. Shalla’s Blacklist – Free, 1.5 million entries, updated daily; – Commercial, 3.7 million entries, updated daily). Multiple methods ensure broad coverage.
  5. Identified websites are added to a centrally maintained database of websites, which are to be blocked. ISP DNS servers contact central database and retrieve blocked sites information in real time/daily. Untrusted DNS servers (that do not adhere to this policy) are disallowed from working in the network.
  6. Further to avoid over blocking, traffic corresponding to suspected IP addresses (to block bypass access via IP address or proxies) is redirected to content monitoring servers, where URL based blocking of web page requests is implemented. Loopholes are plugged and system made robust.
  7. Along with Pornographic sites blocking, government may also consider blocking sites such as Phishing (used for economic frauds) and Proxy/Anonymizer (used by Terrorists and persons trying to bypass and access blocked sites) etc.
  8. Government makes it easy to check if a site is blocked via online system that returns a Yes/No/Partial as status. Requests for new sites blocking are handled in time bound fashion, one week maximum. Similarly, wrongly blocked sites are unblocked in time-bound fashion.
  9. Claim is that with the above, >98% blocking of Pornographic websites content can be achieved at a reasonable/ low cost.


3 thoughts on “Is Web Filtering possible for a country?

  1. Sameer April 7, 2015 / 10:01 am

    This is really a good move in a good direction.

    Hope we all together may succeed in protecting our kids from such illicit exposures.


    • Kasyap Karri August 11, 2015 / 5:42 pm

      This is a very good beginning. we need to gather more support for this by factual and convincing arguments.. whatever arguments put forward by Mr.Chetan Bhagat and a few others including the debate moderators ( media) against the ban of porn , were quite shallow.


      • bharatboy August 11, 2015 / 7:16 pm

        I agree we need to build arguments that are logical and make sense. However, please don’t go with Media reports alone, they are representing only side of the picture that interests them (rather titillates their readers interest!). I know a lot of people who are putting their time and energy into this and helping us get the right level of understanding on this issue. However this is only a drop in the ocean and much more work needs to be done.


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