Business Case Studies

What is Internet Censoring and How Does It Work?

Internet censoring is a technique that is used to prevent users from accessing certain websites, services, or content.  This can include government censorship of entire sites, domains, or categories of content, as well as much smaller-scale censorship, such as blocking certain domains on an office or school network.  There are several ways in which this can be accomplished, and several rationales for why it is done in the first place.  Likewise, there are also ways for users to bypass these kinds of restrictions, as we’ll describe in more detail below.

Purpose of Internet Censoring

There are many reasons why internet censoring occurs.  At the government level, it is often practiced by otherwise-restrictive regimes that want to limit citizen’s access to information or material that they deem a threat to state security.  In practice, this often means limiting access to the free press, outside/international media, material that may be critical of the leadership of a country, contrary to religious teachings, and so forth.  The most well-known examples of this kind of internet censoring can be found in China.  Among tech experts, the prolific censorship has become known as the “Great Firewall of China.”  Sites that advocate dissent, are critical of the government, or promote interests or the free exchange of ideas that the government decides are unacceptable are typically banned.

At the same time, internet censoring can be used for far more benign reasons, especially on smaller scales.  Network administrators for businesses, college and university networks, and so on often use a form of internet censoring to restrict access to certain domains.  This is most often done for one of two reasons.  Either the goal is to restrict services and sites that are non-germane to the network’s use, that would otherwise use considerable bandwidth, or to restrict access to sites and services that are considered outside the scope of the network’s purpose, and serve as distractions for users.

The best examples of this are businesses that block “time wasting” sites like Facebook, various gaming sites, YouTube, social media, and/or pornographic materials from their network.  They want their employees to be focused on work, not wasting time on social media or similar activities.  Similarly, services like peer-to-peer file sharing clients, such as BitTorrent, are often restricted or blocked, as they use a considerable amount of network bandwidth, and don’t generally have a legitimate use in the workplace.

Finally, there is a type of internet censoring that is less about censoring and more about access controls based on geography.  Geo-restricting content is a common practice among sites and services that are devoted to media and entertainment.  These kinds of controls limit the available content to libraries or catalogs based on the user’s country.  They enable streaming media companies and other entertainment companies to enforce regional and geographic restrictions placed on content by distributors, publishers, and licensors.  This is why, for example, Netflix users in the US see a different catalog of content than those in Canada.

Methods of Internet Censoring

All of the above types of internet censoring can be accomplished in several different ways. Let’s start with the last example first.

Geographic restrictions and limitations on content are usually accomplished via IP address geo-location.  Every Internet connection has an IP address, at the point where the connection meets the wider network.  While many actual users or computers can be behind a single IP address (with the use of routers and other network equipment), the IP address effectively serves as an identifier for that network access point.  All IP addresses are provisioned and managed by central authorities around the world, and assigned to Internet Service Providers (ISPs) in blocks.  These blocks have data related to them stored in databases that are freely accessible online.  In essence, it is possible to easily trace a specific IP address to the ISP who owns it, and the geographic region (sometimes country, sometimes state, sometimes even city) to where it is assigned.  Sites can use this information to determine the country associated with an IP address, and only present the content licensed for that particular country.

In terms of network administration censoring of sites and services, the technology and methods used are largely the same as those used by governments.  Domains, IP addresses, and other information are identified and added to software blockers or filters.  These prevent outbound connections originating from the network from accessing those sites (and often log such attempts).  More advanced methods include routing all traffic from a network, or a country for that matter, through third-party filtering operations.  These may operate on either blacklist principles (adding restricted domains and services to a growing list, and actively preventing connections from going through) or whitelist principles (only allowing access to sites and services on the list of “allowed” connections).  There are often services or government employees behind-the-scenes actively managing these lists, adding new sites and services to ban on a regular basis, coupled with automated, keyword and contextual algorithms that do a lot of the work.

Ways to Bypass Internet Censoring

Fortunately for users, there are several ways to bypass internet censoring efforts.  This can be especially important for political activists in countries that restrict freedom of speech or expression.  We should note, however, that all activities that bypass restrictions on a network do potentially expose users to punishment or reprisals from the network administrator, ISP, or government involved, so caution must be exercised.

With that said, one of the most common and safe ways for users to bypass internet censoring efforts is through the use of a Virtual Private Network, or VPN service.  These services allow users to connect to a VPN server via an encrypted connection, so ISPs, network administrators, and governments can’t decipher their traffic.  For more on VPN services, check out review sites dedicated to the topic like  All they can see is a connection to a server somewhere – but not where the user’s traffic goes after that, nor the content of that traffic.  Since most VPN services have servers located in many countries around the world, users can connect through one of these servers in another jurisdiction, and freely access Internet content and services.  They can also use these services to bypass geo-restricted content, as their IP address appears to the destination site or service as originating at the VPN server they connect through.

Other methods for bypassing internet censoring include using a proxy server, which operates similar to a VPN but without the encryption; utilizing an anonymizing network service such as Tor; asking network administrators for legitimate sites and services to be whitelisted or unblocked; utilizing cellular or satellite-based Internet access services outside the control of government or local network censoring efforts; and using an alternative Domain Name Server (DNS) such as OpenDNS, in the case where blocking is happening at the DNS level.