When governments suddenly block previously uncensored, habitual-use platforms, affected users acquire VPN/proxy tools to restore access — and those tools then incidentally unlock all long-blocked content. The authors call this the 'gateway effect': sudden censorship backfires not through political backlash but through habit-driven evasion that permanently expands information access. The effect is strongest for indispensable, hard-to-substitute services.

New Twitter users who joined because of the Instagram block were initially apolitical (80% Chinese-language preference vs. 39% for existing Chinese Twitter users; ~80% of first follows were entertainment/sports accounts) but within two days their rate of political discussion about Hong Kong converged with that of established users. This confirms the gateway effect operates without pre-existing political motivation and without a Streisand-style backlash.

4. Politicization policy

Blocked Chinese-language Wikipedia pages received approximately 160,000 more views on September 29, 2014 (the day Instagram was blocked) than in the preceding week, covering politically sensitive topics — Tiananmen Square, mainland leaders, and the PRC blocked-sites list — that long-term VPN users would not be browsing for the first time. By November 1, Chinese-language Twitter accounts had accumulated 33,750 more followers than pre-block trend projections.

4. Politicization / Figure 4 / Figure 5 evaluation

China's September 29, 2014 Instagram block caused VPN Express to jump from rank 1,229 to rank 6 among all iPhone app downloads in China in a single day, and four of the top ten free productivity apps that day were VPNs (VPN Express, GreenVPN, VPNArtifact, VPN in Touch). The prior day, no VPN appeared in the top 10.

2. Effects of the Instagram block on VPN acquisition evaluation

On the day Instagram was blocked, geo-located Twitter users from mainland China increased ~30% and new account creation jumped more than 600%. A full 53% of previously active Instagram users (estimated 8–16 million people) continued accessing Instagram via evasion tools after the block, compared with roughly 0.026% of all Chinese Internet users who used Twitter before the block — demonstrating the Firewall's baseline efficacy and the magnitude of the gateway-driven surge.

3. Expanded Access to Blocked Websites / 1. Direct effects of the Instagram block evaluation

The June 2025 Iran shutdown—carried out during the Iran-Israel war beginning ~June 19—did not use BGP route withdrawals as in 2019. Instead, authorities applied service-level restrictions at the national border: DNS poisoning of foreign destinations, protocol whitelisting permitting only pre-approved domestic services, and DPI to block circumvention-tool traffic. Iran's international traffic fell roughly 90% while the country's BGP routes remained advertised, making the shutdown invisible to BGP-based monitoring systems. OONI measurement volume, which totalled 121,333 in June 2025, collapsed to under 200 submissions on June 19-20.

2025-iran-shutdown-measurement Executive Summary / §2 dpidns-poisoningport-blockingip-blocking

Chinese users treat full proxy/VPN (Shadowsocks, V2Ray/Clash, commercial VPNs) as the '终极大杀器' (ultimate solution) for bypassing GitHub DNS poisoning, implying that lighter-weight DNS-only fixes fail in some network environments where the censor adds firewall-layer blocking beyond DNS.

2026-anon-6-github-dns §3 使用代理或 VPN dns-poisoningip-blocking

Rule-based proxy tools (Clash, Shadowsocks, V2Ray) are documented as the most reliable solution for accessing GitHub from China, with split-tunneling rules routing only GitHub traffic through the proxy while keeping domestic traffic on the direct path. Git command-line tools require explicit proxy configuration (git config --global http.proxy http://127.0.0.1:7890) to route clone/push operations, as they do not inherit system proxy settings automatically.

2026-anon-github-2026-6-dns §方法二 dns-poisoningip-blocking

The GFW blocks GitHub via DNS poisoning across at least four domains — github.com, assets-cdn.github.com, github.global.ssl.fastly.net, and raw.githubusercontent.com — causing connection timeouts and page-load failures for mainland China users. The block is persistent as of February 2026, affecting both browser access and command-line git operations.

2026-anon-github-2026-6-dns Introduction / §方法一 dns-poisoningip-blocking

Article 19 documents that Iran's National Information Network (NIN / SHOMA) was designed with explicit reference to China's Great Firewall as a model, with institutional mirroring: Iran's Supreme Council of Cyberspace parallels China's Cyberspace Administration of China, and both governments share a "cyber sovereignty" doctrine used to justify domestic content controls and cross-border technology transfer. The report frames Iran's filtering infrastructure as deliberately architected to replicate GFW capabilities, not as an independently developed system.

2026-article19-tightening-the-net §2, §3 dpisni-blockingdns-poisoningip-blockingbgp-hijackthrottling

Article 19 documents that Iran combines technical filtering with formal coercion of major foreign platforms (including Telegram, Instagram, and WhatsApp) to comply with content removal orders under threat of full blocking. The report notes that Iran's 2022 Women Life Freedom protests accelerated platform blocking when foreign operators refused compliance, demonstrating that the censorship system operates in two modes: coerce-and-allow for compliant platforms, block for non-compliant ones. Domain fronting via these platforms is therefore subject to sudden revocation if political conditions change.

2026-article19-tightening-the-net §6 ip-blockingdns-poisoningthrottling