Internet Fragmentation > Sony’s Case Against Quad9

What Happens When a Court Orders a DNS to Block Content?

Region: Europe
Threat type: Regulation of DNS Infrastructure
Last updated: 1 December 2023

A court ruling in Switzerland could have an impact across borders.

There are a small number of large, public DNS resolvers that anyone can connect to, for free. Sometimes they offer better performance or security. If you care about DNS privacy, surveillance or you live in a place that’s subject to censorship, you might have intentionally connected to one of these to continue using the Internet more freely.

Quad9 is a Swiss-based public DNS resolver that offers optional malware blocking. In June 2021, a German court imposed an injunction on them, on behalf of Sony Music. It demanded that they block a website that contained links to pirated music both inside and outside Germany.

Quad9 objected on several grounds, including that they’d been singled out among public DNS resolvers, and that they shouldn’t be forced to change their technical model across borders. They also warned that if this ruling is upheld, it could have broader implications, not just across Europe, but for the trustworthiness of the Internet as a whole.

Because the order would add a technical burden for Quad9 in the long term, they added what they called a ‘hack’ so that they would be compliant in the meantime—although they openly disagreed with the ruling.

They have also argued that while there are legitimate ways to block or filter certain types of content, these shouldn’t be done at the level of the DNS because it undermines its neutrality.

In addition to the threat from a large company using the courts to change the nature of the Internet for their commercial interests, this is also a fragmentation threat. It means that a single content policy applied to one DNS resolver can change the experience of the Internet for users all over the world. This also means that there isn’t even a chance for humans to use their judgment in moderating content.

This type of ruling isn’t limited to Quad9, and it’s been seen outside of Germany, too.

For example, Cloudflare is a US-based company that, among other things, provides a public DNS resolver that offers a DNS blocking service for its users. This service is generally aimed at families, and they can choose whether or not to use it.

But, in 2022, an Italian court ordered Cloudflare to block three torrent sites on its public DNS resolver service. When Cloudflare appealed the ruling, the court rejected it, forcing them to block the sites.

These public DNS resolvers are used all over the world, not just in Germany or Italy, so the orders to block access in those services apply to users all over the world.


As of mid 2023, after more than two years of legal action, the injunction has been upheld by the Dresden Court of Appeal. Sony was also successful in the main case before the Leipzig Regional Court. In June 2023, Quad9 appealed to the Dresden Higher Regional Court. Quad9, despite a Geo-IP lock.

And, faced with administrative fines for non-compliance in Germany the resolver felt it had no choice other than to implement a global block, not just for German users, but for anyone who uses its services. An appeal is still pending.

Our Position

When a court orders a DNS resolver to block content, this fractures how routing and addressing works. It means that IP addresses don’t resolve consistently, authoritatively, and dependably, everywhere.

When they’re forced to block an entire domain name or website, just to cut off access to specific pages or types of content, this also causes ‘collateral damage’ by making all of the legitimate content also inaccessible. And this, too, fragments the global identifier systems.

These decisions also affect users all over the world, not just where the decision was made. This means that one country is imposing its decisions about what its population can access onto another country’s population.

This type of filtering is generally inefficient and ineffective. And overall, it interferes with the stability, security and resilience of the Internet. This practice undermines the critical properties needed to deliver the Internet’s benefits to the widest range of people.

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Talking Points

  • These types of DNS recursive resolvers translate domain names into IP dresses. This is an important job for the functioning of the Internet. But these resolvers shouldn’t act as gatekeepers for content globally, since those decisions can be subjective, and they also vary between jurisdictions. One country’s legal decision shouldn’t be imposed on everyone else in this way.
  • Blocking an entire website based on its content is censorship. It means that people can’t access specific information, based on someone else’s values, rather than allowing individuals to choose what they access online.
  • It’s crucial to recognize that DNS recursive resolvers like Quad9 aren’t the right place to implement content-blocking measures. This type of blocking puts too heavy a burden on the resolver to police content online. The operators also don’t have the legal expertise or access to the information needed to decide what content is legal or illegal.