A multi-perspective view of Internet censorship in Myanmar

In the wake of a military coup in February 2021, Myanmar experienced unprecedented levels of internet censorship.

In response, we collaborated with CAIDA’s Internet Outage Detection and Analysis (IODA) team and Myanmar ICT for Development Organization (MIDO) on publishing a research report which documents a series of nightly internet outages and the blocking of social media, Wikipedia, and circumvention tool sites in Myanmar following the military coup.

In the months that followed, we continued to examine internet censorship in Myanmar quite closely. We collaborated with IODA, Kentik, and other researchers from UC San Diego and the University of Michigan to expand our analysis. We used diverse datasets and measurement methods to offer a holistic view into the censorship events in Myanmar that occurred since the coup and show how internet censorship evolved between 1st February 2021 to 30th April 2021.

As an outcome, we produced a research paper (“A multi-perspective view of Internet censorship in Myanmar”) which we submitted to the ACM SIGCOMM 2021 Workshop on Free and Open Communications on the Internet (FOCI 2021). Our paper was published by FOCI 2021 and CAIDA’s Ramakrishna Padmanabhan presented our research findings at the workshop.


Below we summarize the key findings of our paper.

Summary of findings

You can learn about the findings of our research paper by viewing the following video produced by CAIDA’s Ramakrishna Padmanabhan.

Internet outages

Following the military coup on 1st February 2021, Myanmar experienced a series of internet outages until 28th April 2021.

Internet outages in Myanmar

Source: Internet Outage Detection and Analysis (IODA), IODA Signals for Myanmar, https://ioda.caida.org/ioda/dashboard#view=inspect&entity=country/MM&lastView=overview&from=1613125943&until=1615545143

In summary, these include:

Website and social media blocking

Starting from 4th February 2021 (3 days after the coup), ISPs in Myanmar started blocking access to a number of websites – including Wikipedia, social media (such as facebook.com and twitter.com), and circumvention tool websites. These blocks remain ongoing.

We share these blocked websites through the following chart, which summarizes OONI measurement findings between February 2021 to April 2021.

Website blocks in Myanmar

Source: Blocking of websites in Myanmar from February 2021 to April 2021 based on OONI measurements.

In terms of censorship techniques, we found:

Overall, we found:

Twitter hijack and collateral damage

On 5th February 2021 —the same day that Twitter was blocked in Myanmar— Myanmar’s Campana Mythic (AS136168) announced the prefix, belonging to Twitter. The proximity of this hijacking event in time to the blocking of Twitter in other Myanmar ISPs suggests that the original intent was to blackhole traffic to Twitter for users of this Myanmar ISP. However, this route accidentally leaked to the global internet, appearing as if AS136168 owned/hosted Twitter’s address space. This accidental event offers additional evidence that providers used various ways to perform IP-level blocking to censor domains.

Our analysis of BGP data collected by the Routeviews and RIPE RIS projects shows the illegitimate route propagated (at least) to operators in Singapore (AS4844, AS56300, AS24482, AS132132) and Vietnam (AS45903) who received, accepted, and further propagated it. This resulted in collateral damage for Twitter users outside Myanmar.

We quantify the extent of this collateral damage in the following graph, which shows that a small volume of traffic from Kentik’s customers outside Myanmar was directed towards the hijacker (AS136168) instead of Twitter (AS13414).

Twitter hijack and collateral damage

Source: Collateral damage to Twitter users outside Myanmar as a result of the BGP hijack event affecting Twitter’s address space. The figure shows Twitter traffic observed by Kentik from different source ASes (indicated by different colors) that was being routed towards Campana Mythic (AS136168).


The following timeline summarizes the main internet censorship events that we detected in Myanmar following the February 2021 military coup.

Timeline of censorship events in Myanmar

Image: Timeline of censorship events in Myanmar.

Collectively, these are among the most disruptive, long-lasting, and widespread censorship events in recent times.

The censorship events in Myanmar reflect emerging patterns of politically inspired censorship and offer insight into the ways in which authoritarian regimes combine censorship approaches strategically to achieve their immediate goals. The timing of censorship events in Myanmar coincided with the military coup, which is consistent with many other studies which have shown that internet censorship is targeted during sensitive political time periods and periods of potential power transitions, such as elections and large-scale protests.

The fact that the initial outages were implemented by the challenger rather than the incumbent government suggests that internet censorship during a coup attempt can increase the probability of a successful coup. Conspirators in a coup may benefit from shutting communications quickly, to prevent public or government coordination against their coup attempt. Yet, the haphazard nature of the outages during the initial coup in Myanmar may reflect the difficulty of the challenger in implementing this censorship, and could be a reflection of their initial lack of political control.

After consolidating power, the new junta in Myanmar began imposing internet curfews, shutting down the internet during the night while keeping it on in the day. Like physical curfews, regimes may implement internet curfews to target organization of political dissent while minimizing the impact on the economy, as many sectors require internet access during the day.

While nightly outages in Myanmar have now ended, the ongoing blocking of social media and circumvention tool websites (which has persisted since February 2021) may indicate a move toward more selective methods of censorship. This shift is consistent with a pattern in authoritarian regimes of engaging in targeted censorship to maximize political impact while minimizing its cost.

We hope this paper can provide a template of combining internet measurements to provide a broader understanding of digital strategy of autocrats, an effort that could be scaled and replicated cross-nationally in future work.