Application-layer blocking — where censors restrict specific applications or services without disrupting IP connectivity — is invisible to network-level measurement systems like IODA that monitor BGP, active probing, darknet telescope, and Google Search traffic, making it a growing blind spot in automated shutdown detection.

Comparative analysis of 73 unmatched events (2022 onward) between IODA's automated network-level detection and Access Now's #KeepItOn Shutdown Tracker reveals systematic documentation gaps — shutdowns recorded by human reporters are frequently absent from automated measurement platforms and vice versa.

Abstract / §1 Introduction evaluation

AS-targeted shutdowns — where censors restrict connectivity at specific ISPs or autonomous systems rather than imposing country-wide outages — evade country-level aggregation in automated detection systems, which are calibrated to detect national-scope disruptions.

§3 Detection Gap Categories evaluation

Prolonged conflicts with gradual infrastructure recovery represent a third category of detection gap: IODA-style automated systems struggle to distinguish ongoing partial outages from normal network fluctuation, causing recovery-phase disruptions in conflict zones (e.g., Myanmar, Sudan) to go undocumented in automated records.

§3 Detection Gap Categories evaluation

The largest single source of censored domains in the GNL is MESA lab's SNI monitoring dataset (E21-SNI-Top200w.txt) containing 57,362 censored domains, and E21-SNI-Top120W-20221020.txt with 36,467 domains—totaling over 93K domains from network tap data alone for a single country (E21 = Ethiopia per InterSecLab attribution). A separate Xinjiang dataset (XJ-CUCC-SNI-Top200w.txt) contains 13,604 domains. These datasets "do not seem to come from popular domain lists, and instead appear to be gathered from network taps," confirming that Geedge builds censorship target lists directly from passive traffic observation.

2026-sheffey-geedge §4.2, Table 3 dpisni-blockingmeasurement-platform

Of 6,915,266 domains extracted from the 572 GiB Geedge Networks Leak (GNL), 298,955 censored domains (93.7% of all GNL-censored domains) appear in neither Tranco top-1M nor CitizenLab test lists. Measurements across China (Guangzhou/Nanjing), Myanmar, Pakistan, and Algeria confirmed censorship via DNS injection and SNI-based TLS connection termination. The GNL covers 25–62% of Tranco-censored domains across countries, showing substantial but incomplete overlap. This vendor-side ground truth reveals a censorship surface roughly two orders of magnitude larger than curated academic test lists.

2026-sheffey-geedge §4.1, Table 2 dpisni-blockingdns-poisoningmeasurement-platform

Wrana et al. systematically assess how well existing surveillance and censorship mechanisms can target users of Future Internet Architectures (FIAs) — including NDN, SCION, XIA, and MobilityFirst — finding that DPI and flow-correlation techniques from the current internet map onto FIA traffic with moderate adaptation. The paper identifies that FIA naming/addressing schemes introduce new censorship attack surfaces (e.g., content-name-based filtering in NDN) not present in IP-based architectures.

2025-wrana-sok-surveillance §4, §5 dpiflow-correlationmeasurement-platform

CenDTect, an unsupervised decision-tree system using iterative parallel DBSCAN, analyzed more than 70 billion Censored Planet data points (January 2019 – December 2022) and discovered 15,360 HTTP(S) censorship event clusters across 192 countries and 1,166 DNS event clusters across 77 countries. Manual validation against 38 known censorship events from news reports confirmed all human-identified events were recoverable from CenDTect's output. The system additionally identified more than 100 ASes in 32 countries with persistent ISP-level blocking and 11 temporary blocking events in 2022 correlated with elections, protests, and armed conflict.

2024-tsai-modeling Abstract, §5, §6 measurement-platformdpidns-poisoning

The paper introduces TMC, a remote measurement tool that infers domain-blocking status across DNS, HTTP, and HTTPS without requiring in-country vantage points, using only 38% Internet penetration in a country of 6 million people. TMC enabled the largest Turkmenistan censorship measurement to date by exploiting middlebox reflection properties observable from outside the country.

2023-nourin-measuring §TMC measurement-platformdpidns-poisoning

Scanning the IP address spaces of 18 countries surrounding Russia, the authors identify Russian transit censorship affecting at least 8 countries (Afghanistan, Azerbaijan, Kyrgyzstan, Kazakhstan, Lithuania, South Korea, Tajikistan, and Ukraine), attributable to at least 6 Russian ASes. Only 2 of these 8 countries (Kyrgyzstan and Kazakhstan) had been reported in prior work, and the collateral damage is characterized as a lower bound due to the study's blockpage-only methodology.

2023-ortwein-towards §5 Preliminary Results dpipacket-injectionmeasurement-platform