A multi-perspective view of Internet censorship in Myanmar Ramakrishna Padmanabhan Arturo Filastò CAIDA, UC San Diego ramapad@caida.org OONI arturo@openobservatory.org Ram Sundara Raman Kennedy Middleton Doug Madory Molly Roberts University of Michigan ramaks@umich.edu Kentik dmadory@kentik.com UC San Diego kmiddlet@ucsd.edu UC San Diego meroberts@ucsd.edu OONI maria@openobservatory.org Mingwei Zhang CAIDA, UC San Diego mingwei@caida.org Alberto Dainotti CAIDA, UC San Diego alberto@caida.org On February 1, 2021, the Myanmar military seized power [50, 54, 55]. The same day—before “Internet curfews” became the norm in the country [84]—Internet connectivity was severely disrupted for several hours. Following the coup, the military also ordered the blocking of Facebook, Twitter, and Instagram [12, 22, 30]. The Internet censorship events that occurred in the aftermath of this coup are among the most disruptive, long-lasting, and widespread events in recent times. While early studies of Internet censorship events had to be performed by analyzing news reports [34], or by using ad hoc datasets [16, 35–37], there exist several tools and datasets today whose purpose is to shed light on these types of events [7, 8, 10, 52, 56, 73]. As Internet censorship has evolved, so have the tools to observe them, enabling fine-grained analysis leading to valuable insights and lessons. In this paper, we use publicly available datasets from IODA [10] and OONI [21, 61], and a proprietary dataset from a large network observability company—Kentik [40]—to dissect and analyze technical data about Internet censorship events in Myanmar following the coup. We use these complementary datasets to offer a holistic view (Figure 1). We present empirical data on large-scale Internet connectivity shutdowns including nightly Internet curfews and cellular outages, rampant censoring of websites, and even a route hijacking incident. We also extract political insights from this technical data. Specifically, we report upon: ABSTRACT In the wake of a military coup in February 2021, Myanmar experienced unprecedented levels of Internet censorship. Beginning with haphazard blocking of social media and intermittent Internet connectivity outages, controls proceeded to stricter blocking of websites, the shutdown of cellular data in several networks, and nearly complete disconnection from the Internet every night. In this study, we use 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 during this time. CCS CONCEPTS • Networks → Network measurement; KEYWORDS Internet censorship, Internet outages, Availability ACM Reference Format: Ramakrishna Padmanabhan, Arturo Filastò, Maria Xynou, Ram Sundara Raman, Kennedy Middleton, Mingwei Zhang, Doug Madory, Molly Roberts, and Alberto Dainotti. 2021. A multi-perspective view of Internet censorship in Myanmar. In ACM SIGCOMM 2021 Workshop on Free and Open Communications on the Internet (FOCI’21), August 27, 2021, Virtual Event, USA. ACM, New York, NY, USA, 10 pages. https://doi.org/10.1145/3473604.3474562 1 Maria Xynou INTRODUCTION • Massive-scale censorship: Nightly country-wide Internet connectivity shutdowns occurred continuously for more than two months, normalizing Internet curfews. Further, we show that access to cellular data has been restricted since March 15, 2021. We also reveal extensive blocking of social media and circumvention tool websites. • Evolution and consolidation of power: The censorship events in Myanmar show signs of evolution over time. From the somewhat haphazard early Internet connectivity outages to the wellcoordinated nightly outages, there has been increasing sophistication. The uncoordinated nature of the early outages are consistent with the potential limited authority and lack of access to the appropriate communication channels that the military may have had in the immediate aftermath of a coup. The subsequent evolution is consistent with the new regime’s consolidation of power. Going forward, in countries with multiple Internet Service Since the first nationwide government-mandated Internet connectivity shutdown in 2005 in Nepal [77] the frequency of such events has been increasing worldwide [1, 2, 14, 61, 73, 79]. Today, Internet censorship takes several forms: from complete disconnection [16, 62], to blocking of specific websites [3, 4, 20]. Few censoring entities, however, have sought to exert control over the Internet in the manner employed by the Myanmar military in the wake of the recent coup. 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