Internet Censorship Explained - Computerphile

Summary

This script delves into internet censorship, detailing the mechanisms of control over user-publisher communication. It explains how censors can halt information flow through DNS redirection, IP blocking, and application layer blocking. The discussion highlights the 'arms race' between censorship and resistance, with technology evolving to counteract control. It also touches on the importance of anonymity and privacy in resisting censorship, suggesting tools like TOR to maintain user privacy.

Takeaways

• 🌐 Internet censorship involves controlling the dissemination of information by targeting the user, publisher, or the information itself.
• 🔍 The censorship process can be broken down into blocking publication, discouraging access, or coercing users to avoid certain content.
• 💻 An example of censorship is blocking access to a website like 'youtube.com' by manipulating DNS queries or IP addresses.
• 🔄 DNS redirection or sinkholing is a method where a censor-controlled server provides a false IP address for a domain, leading users away from the intended site.
• 🚫 IP blocking is a direct method where a censor prevents a user's connection to a specific IP address, effectively stopping access to a site.
• 🔍 Application layer blocking allows censors to inspect content for keywords and disrupt connections carrying censored information.
• 👤 The human element of censorship resistance involves ensuring privacy and anonymity for both publishers and users of information.
• 🔑 Censorship resistance systems aim to provide privacy, but users often need to combine these with additional anonymity services like TOR for better protection.
• 📰 Traditional censorship, like blocking content in newspapers, contrasts with digital censorship which involves more sophisticated technical methods.
• 🏃‍♂️ The battle between censorship and resistance is an ongoing 'arms race', with technology for controlling and accessing information constantly evolving.
• 🐱‍👤 The 'cat and mouse game' between censors and those resisting censorship involves continuous adaptation as each side develops new strategies and technologies.

Q & A

What are the main components of communication as it relates to internet censorship?

The main components of communication in the context of internet censorship are the user, the publisher, and the information being disseminated. The user is the individual seeking information, the publisher is the source providing the information, and the information itself is the content being shared between them.

How does internet censorship aim to control the flow of information?

Internet censorship aims to control the flow of information by either preventing the publication of certain content by publishers, discouraging users from accessing that information, or directly coercing users to not access it. The ultimate goal is to stop the dissemination of information deemed undesirable by the censor.

Can you explain the example given in the script about how censorship might occur if 'youtube.com' is blocked?

If 'youtube.com' is blocked, a user attempting to access it would normally type the URL into their browser, which would then query a DNS server for the corresponding IP address. A censor could interfere at this point by either claiming the domain does not exist or by providing a false IP address, leading to DNS Redirection or DNS Sinkholing.

What is DNS Redirection or DNS Sinkholing in the context of internet censorship?

DNS Redirection or DNS Sinkholing is a censorship technique where a censor-controlled DNS server provides a false IP address for a domain, redirecting the user to a different, often controlled, site instead of the originally requested one.

What is IP Blocking and how does it relate to internet censorship?

IP Blocking is a method of internet censorship where the censor prevents users from connecting to a specific IP address, effectively blocking access to a website or service. This is done at the IP layer, independent of the domain name system.

What is application layer blocking, and how does it differ from DNS or IP blocking?

Application layer blocking is a sophisticated form of censorship that involves inspecting the content of data packets for specific keywords or patterns that indicate undesirable information. Unlike DNS or IP blocking, which operate at lower levels of the network stack, application layer blocking can target specific content within the communication stream.

How can censorship resistance systems help protect user privacy and anonymity?

Censorship resistance systems can protect user privacy and anonymity by making it difficult for censors to trace the identity of users accessing certain information. By combining these systems with anonymity services like TOR, users can maintain a higher level of privacy and reduce the risk of coercion or identification.

What is the 'cat and mouse game' mentioned in the script in relation to censorship and censorship resistance?

The 'cat and mouse game' refers to the ongoing struggle between censors who attempt to control and restrict information and those who develop and use censorship resistance technologies. As censorship methods evolve, so do the countermeasures, creating a continuous cycle of adaptation and response.

Why is it challenging for censors to control information on social media platforms like Twitter and Facebook?

Controlling information on social media platforms is challenging for censors because of the vast amount of user-generated content and the fact that these platforms are hosted by major companies like Google and Twitter. Blocking these platforms entirely would result in significant collateral damage and affect many innocent users.

What does the term 'arms race' imply in the context of censorship and censorship resistance?

The term 'arms race' in this context implies the continuous competition between the development of censorship techniques and the creation of new censorship resistance technologies. As one side advances, the other must innovate to counteract the new measures, creating a cycle of escalating technological advancements.

How can users protect themselves from coercion by censors when accessing the internet?

Users can protect themselves from coercion by using a combination of censorship resistance systems and anonymity services. This includes using VPNs, proxy servers, and privacy-focused browsers, as well as being aware of the legal implications and risks associated with accessing censored content.