In recent years, governments, private entities, and even sports leagues have increasingly used IP and DNS blocking to curb digital piracy. While these measures aim to restrict illegal content, their impact goes far beyond that. According to the latest Internet Society (IS) report, such practices undermine the very foundations of the Internet and often create serious collateral damage for both users and businesses.
How Blocking Works — and Why It’s Problematic
IP Blocking
Implemented by denying connections to specific IP addresses via firewalls, ACLs, or edge router rules.
🔴 Problem: A single IP can host multiple websites or services (shared hosting, CDNs). Blocking it cuts off legitimate services as well.
DNS Blocking
Manipulates name resolution by returning false (NXDOMAIN) or null responses from resolvers.
🔴 Problem: Breaks global DNS consistency and can interfere with DNSSEC, weakening cryptographic validation of queries.
Real-World Examples of Collateral Damage
- Spain (2025): LaLiga and Telefónica enforce IP blocks every weekend against pirate streaming sites. Collateral effect: e-commerce platforms and legitimate projects hosted on the same servers become inaccessible.
- Italy (2024): The Piracy Shield system caused widespread outages, temporarily cutting access to services like Google Drive and Cloudflare while attempting to block illegal football streams.
Technical Impact According to Internet Society
The IS report highlights four main risks:
- Breaking the end-to-end model.
Blocking introduces artificial points of failure, contradicting the original design of the Internet. - Cybersecurity risks.
DNS manipulation weakens DNSSEC validation and may push users toward untrusted resolvers or insecure VPNs. - High operational costs.
ISPs must deploy advanced firewalls, deep packet inspection (DPI) systems, and monitoring tools, adding latency and reducing performance. - Loss of trust in infrastructure.
Businesses and users affected by unjustified blocks may migrate services, fueling Internet fragmentation.
Practical Example 1: DNS Blocking Breaking DNSSEC
Imagine an ISP applying DNS blocking to the domain example.com, returning NXDOMAIN.
$ dig example.com +dnssec
; <<>> DiG 9.18.12 <<>> example.com +dnssec
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 12345
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0
Here, DNSSEC validation fails because the resolver response is inconsistent with cryptographic signatures. The user experiences a resolution error, even though the domain is perfectly functional.
Practical Example 2: IP Blocking on a Shared Server
A server with IP 203.0.113.25 hosts:
online-store.com(legitimate e-commerce)piratestream.com(illegal streaming)
If the ISP blocks the IP to stop the streaming site:
iptables -A INPUT -s 203.0.113.25 -j DROP
Code language: CSS (css)Both sites go offline, penalizing the legitimate business and its customers.
Internet Society’s Recommendations
- Target the source. Take down illegal infrastructure rather than imposing mass access restrictions.
- Due legal process. Blocking should only occur under judicial authorization with independent review.
- Transparency and temporality. Publish block lists, explain criteria, and limit duration.
- Technical alternatives. Provide parental controls or opt-in user-level filters instead of global censorship.
Conclusion
For system administrators, the message is clear: IP and DNS blocking are blunt tools that damage the technical architecture of the Internet. They break DNSSEC, harm legitimate services, add unnecessary operational costs, and introduce new cybersecurity risks.
Protecting an open, resilient, and global Internet requires proportional, transparent measures and more precise technical alternatives—ones that don’t compromise the very trust and reliability the Internet was built upon.
