May 21, 2022

Research Paper: “Censorship in the Wild: Analyzing Web Filtering in Syria”

The following 16 page paper was written by researchers from several organizations and was made available via arXiv late last week.

The authors point out in the abstract that the paper is, “the first look into Internet filtering in Syria.”


Censorship in the Wild: Analyzing Web Filtering in Syria


Abdelberi Chaabane
INRIA Rhone Alpes 

Mathieu Cunche

Terence Chen

Arik Friedman

Emiliano De Cristofaro
University College London

Mohammed-Ali Kafaar
INRIA Rhone Alpes


via arXiv


Over the past few years, the Internet has become a powerful means for the masses to interact, coordinate activities, and gather and disseminate information. As such, it is increasingly relevant for many governments worldwide to surveil and censor it, and many censorship programs have been put in place in the last years.

Due to lack of publicly available information, as well as the inherent risks of performing active measurements, the research community is often limited in the analysis and understanding of censorship practices. The October 2011 leak by the Telecomix hacktivist group of 600GB worth of logs from 7 Blue Coat SG-9000 proxies (deployed by the Syrian authorities to monitor and filter traffic of Syrian users) represents a unique opportunity to provide a snapshot of a real-world censorship ecosystem and to understand the underlying technology.

This paper presents the methodology and the results of a measurement-based analysis of these logs. Our study uncovers a relatively stealthy yet quite targeted filtering, compared to, e.g., that of China and Iran. We show that the proxies filter traffic, relying on IP addresses to block access to entire subnets, on domains to block specific websites, and on keywords and categories to target specific content. Instant messaging is heavily censored, while filtering of social media is limited to specific pages. Finally, we show that Syrian users try to evade censorship by using web/socks proxies, Tor, VPNs, and BitTorrent.

To the best of our knowledge, our work provides the first look into Internet filtering in Syria.

Direct to Full Text (16 pages; PDF)

About Gary Price

Gary Price ( is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at, and is currently a contributing editor at Search Engine Land.