Each round of copyright enforcement drove deeper architectural decentralization: centralized servers (BBSs/FTP) → central directory (Napster) → supernodes (KaZaA/Grokster) → pure protocol (BitTorrent). Even after Grokster was shut down its software continued to work, because no fixed corporate entity remained as the control point.

DNS infrastructure is a primary chokepoint target: U.S. DHS seized domain names of sites including rojadirecta.org — found non-infringing under Spanish law — without Congressional authority. The proposed PROTECT-IP Act (2011) would have authorized DNS injection against 'non-domestic' domains. Developers countered with a browser plug-in distributing alternate domains outside U.S. jurisdiction; Mozilla refused a DHS demand to remove it.

§1.4.1 policy

When RIAA filed suit against more than 30,000 individual filesharers, users migrated toward anonymous channels, small-world networks of vetted peers, ephemeral pointers, and user-generated IP blacklists for spoofed-peer detection. The University of Washington demonstrated IP-to-person attribution is unreliable — a networked laser printer received a DMCA takedown notice.

§1.3 defense

Censorship operating at the infrastructure layer (hosting, DNS, ISPs) rather than the content layer produces opacity: blocklists must be kept secret lest they become menus of blocked content, accuracy cannot be examined, and harms are divided from those with incentive or expertise to oppose them. The consistent pattern in anti-censorship responses is to distribute, decentralize, encrypt, and obfuscate — making circumvention traffic indistinguishable from permitted use.

§2.1 policy

The U.S. 'five strikes' program had major ISPs reduce bandwidth of accused subscribers; challenging required a $35 fee with only one permitted defense category ('unauthorized use of account'). Users responded by routing traffic through VPNs and anonymizing networks such as I2P to bypass ISP-level monitoring entirely.

§1.4.2 policy

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

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

Brussee measures a systematic pattern of Chinese government websites actively blocking access from outside China (the "reverse Great Firewall"), publishing a CSV dataset of affected domains (available at zenodo.org/records/18172145). The paper frames this outbound geo-blocking as a cybersecurity-motivated practice — Chinese authorities classify foreign access to domestic government infrastructure as an attack surface — distinct from the inbound information control goal of the GFW.

2026-brussee-reverse-great-firewall §3, §5 ip-blockingasn-blackholing

Brussee develops a conceptual framework distinguishing two logics of government geo-blocking: (1) information control (blocking inbound foreign content from domestic users) and (2) data sovereignty / attack-surface reduction (blocking outbound access by foreign actors to domestic systems). Chinese government site blocking of external IPs is motivated primarily by the second logic, creating an asymmetric internet topology where CN citizens cannot reach the outside world, and outside actors cannot probe CN government infrastructure.

2026-brussee-reverse-great-firewall §2, §4 ip-blockingasn-blackholing

ShieldShare demonstrates that an Android application can route all hotspot-client traffic through a VPN tunnel without root access by using a SOCKS5/HTTP/HTTPS proxy layer between the hotspot and the VPN, with per-client traffic accounting and quota management. The system works because Android's native hotspot does not forward VPN routing tables to connected clients; ShieldShare interposes a proxy that handles this. Released as open-source.

2026-edorh-shieldshare §Abstract ip-blocking