On July 31, 2025, Germany's Federal Court of Justice delivered a decision that drew back into question the legality of ad blockers.

The court overturned a 2023 ruling that dismissed German publisher Axel Springer's copyright claims against Adblock Plus owner Eyeo, sending the case back to Hamburg's Higher Regional Court for fresh examination.

At stake is whether website code qualifies as protected computer programs under copyright law — and whether ad blockers violate that protection by modifying that code.

It's an unexpected development that's been a long time in the making. Axel Springer has relentlessly pursued legal action against ad blockers for over a decade, refusing to accept defeat despite multiple court losses. They really want them outlawed.

Springer's persistence stems from significant financial stakes — ad blockers cost the company many millions in lost revenue annually. Germany compounds this problem for them as the ‘unofficial home’ of ad blocking (it’s where Eyeo is based). Adoption rates there are among the highest of any major economy. This makes it a kind of ground zero for publisher losses to blocking technology.

How We Got Here

The timeline of this legal marathon spans more than a decade:

• 2015: Axel Springer begins legal campaign against Adblock Plus, arguing ad blocking violates competition law

• 2018: Germany's Federal Court of Justice rejects competition law claims, ruling ad blocking is legal

• 2019: Springer pivots to copyright strategy, claiming website code is a protected computer program

• 2022: Hamburg Regional Court dismisses copyright claims

• 2023: Hamburg Higher Regional Court again rules in favor of Adblock Plus

• July 2025: Federal Court of Justice overturns 2023 decision, orders retrial

Latest Battleground

The Federal Court of Justice didn't rule that Axel Springer was right. Instead, it criticised the Hamburg court for sloppy reasoning.

The lower court had concluded that Adblock Plus doesn't infringe copyright because it only modifies the browser's runtime display structures (the DOM and CSSOM) rather than the root origin website code. But crucially, the court never definitively ruled on whether website code qualifies as a protected computer program in the first place.

The Federal Court said this approach was backwards. You can't dismiss copyright infringement while simultaneously assuming copyright protection exists without first clearly defining what's being protected.

Specifically, the top court noted that Springer's technical argument — that browsers operate as “virtual machines” executing website bytecode — hadn't been properly examined. If true, this framing could make ad blocking look less like user preference filtering and more like unauthorized program modification.

What Happens Next

The Hamburg Higher Regional Court must now address the fundamental question it previously sidestepped: does website HTML, CSS, and JavaScript code qualify as a "computer program" under Section 69a of the German Copyright Act?

The court has three possible paths:

1. Rule that website code isn't a computer program — eliminating copyright protection entirely

2. Rule that it is a protected program, but ad blocking doesn't constitute infringement — similar to its previous position but with proper legal foundation

3. Rule that it is a protected program and ad blocking does infringe — handing Springer a victory

The decision will hinge on technical analysis of how browsers process website code and whether DOM manipulation constitutes modification of the protected work itself.

The definition of "computer program" in Section 69a is particularly broad — covering "programs in any form" that result from "intellectual creation."

Under this expansive language, the Hamburg court would seem within its rights to classify website code as protected software. But they will likely consider the intended meaning behind the law rather than just its literal text.

Technology moves fast, and there's no way laws written years ago (the early 90s) can deal with future developments in a measured way. The statute was principally designed to protect traditional software development, well before ad blockers existed, not to give publishers veto power over how users experience web content on their own devices.

Legal Strategy

Springer's "virtual machine" argument is telling. It’s the foundation of their legal case. A calculated reframing designed to transform their claim into plausible copyright infringement.

If websites are just “content”, ad blockers look like user preference tools — similar to adjusting font size or enabling dark mode. That’s a comfortable definition for Eyeo.

But if websites are "computer programs executing inside the browser virtual machine," then ad blockers appear to be altering another program's code at runtime under Section 69c(2).

The virtual machine framing makes Springer's technical argument sound credible by borrowing from established computing concepts like the Java Virtual Machine. It moves their claim into recognisable legal territory.

Eyeo's best chance at a counter-strategy likely involves demonstrating the broader implications. If every website that is rendered in a browser becomes a protected computer program, then every browser extension and user customization is in copyright violation. Basically, they need to demonstrate how the open web “breaks” under this premise.

The more the court internalises this logic, the more likely they are to reject Springer's fundamental premise.

So, what breaks?

Broader Implications

If Hamburg rules that websites are copyright-protected computer programs (a BIG “if”), the implications stretch far beyond ad blocking.

The same DOM manipulation techniques used by ad blockers are fundamental to thousands of browser extensions:

• Password managers that inject login fields

• Accessibility tools that adjust fonts and colors for disabled users

• Translation extensions that replace text with different languages

• Dark mode tools that invert page colors

• Grammar checkers like Grammarly that modify text fields

A redditor took a stab at laying out all of the things that would be in infringement:

Yes, this affects AI too!

Most large language model (LLM) crawlers like ChatGPT disable JavaScript when they visit websites. Doing this blocks ads and other dynamic content. Under Springer's legal logic, these AI crawlers would likely meet the definition of modifying website code execution — making it a copyright violation.

But, that’s just the tip of the iceberg.

Andrey Meshkov, CTO of popular ad blocker developer AdGuard, said declaring website code protected under the German Copyright Act “would outlaw most browser extensions, nearly all modern browsers, and — ironically — the web standards themselves.”

This is because browsers function like translators of the web, not a machine producing carbon copies of it. That is a fundamental part of its design.

Springer’s take?

Philipp-Christian Thomale, Senior Legal Counsel for Axel Springer, announced: “What matters is whether object or source code is altered—not merely whether the program’s behavior is influenced.”

In other words: just changing the appearance or output of a website (as ad blockers do by manipulating the page's display in the browser) isn’t the same as altering the underlying code that was written and delivered by the publisher.

Given the way browsers work, it is difficult to see how these are indistinguishable.

A Contradiction

Ironically, the same Federal Court of Justice issued another ruling on July 31st (yes, the exact same day) that appears to contradict the logic behind Springer's case.

In Action Replay II, the court ruled that cheat devices for video games don't violate copyright even though they modify how games behave. The reasoning: as long as the tools only change variable data in memory during runtime without altering the underlying program code, no infringement occurs.

This precedent strongly supports Adblock Plus. Like cheat devices that modify game states in RAM, ad blockers modify webpage display in the browser without touching the original server-side code. Yet the Federal Court treated these cases differently, suggesting website code might receive stronger protection than game code. It certainly can’t be accused of not being thorough.

This Isn’t Just A German Thing

A ruling in Axel Springer’s favour wouldn’t necessarily remain confined to Germany.

The German provisions at issue come directly from EU Directive 2009/24/EC on the legal protection of computer programs, which harmonises copyright law across all 27 member states. That means any interpretation developed in Germany could quickly gain traction elsewhere.

A precedent from the German Federal Court of Justice isn’t automatically binding outside Germany. But it would be highly persuasive to other national courts applying the same Directive — and could trigger copycat litigation across the continent.

More importantly, if the Hamburg Higher Regional Court decides that websites qualify as computer programs, it may seek guidance from the Court of Justice of the European Union (CJEU) through a preliminary reference. A CJEU ruling would be binding across the entire EU, instantly transforming how browsers, extensions, and user customisation are treated in law.

In short: while this starts as a German case, the question it raises — whether website code is a “computer program” under EU law — has the potential to redefine the open web across the EU.

And beyond the EU?

🇬🇧 United Kingdom: The UK’s copyright regime remains closely aligned with the EU Software Directive because Brexit didn’t unwind existing law. Section 3 of the UK Copyright, Designs and Patents Act protects computer programs in similar terms to Section 69a of the German Copyright Act.

UK judges aren’t bound to follow EU or German precedents anymore, but they often look to them as persuasive authority — particularly where the statutory wording is nearly identical. A German or CJEU ruling could therefore spark test cases in British courts.

🇺🇸 United States: US copyright law protects “computer programs” under Title 17, §101, but with a tighter definition than the EU. A program is defined as: “a set of statements or instructions to be used directly or indirectly in a computer in order to bring about a certain result.”

That’s narrower than the EU’s “programs in any form … resulting from intellectual creation.” Under the US definition, HTML and CSS are unlikely to qualify — they’re declarative markup, not executable instructions. JavaScript comes closer, but US courts have historically been cautious about extending “computer program” protection to web code as a whole.

Even if publishers managed to stretch the definition, American law offers additional safeguards: fair use, the first-sale doctrine, and a strong judicial tradition of protecting user autonomy over how they run software on their own machines. This makes a Springer-style “browser virtual machine” argument far harder to win in the US than under the EU framework.

🌏 Globally: If Springer secures a favourable precedent in Germany — or, more dramatically, at the CJEU — it could embolden copycat litigation worldwide. At minimum, the decision would shift the debate: courts and regulators everywhere would have to grapple with the idea that ad blocking isn’t just a competition or consumer-choice issue, but potentially a copyright infringement one.

Adblock Analyst View

This case represents more than a dispute between a publisher and an ad blocker. It's a battle over the fundamental nature of web browsing itself. For decades, the Internet has operated on the principle that users control how they consume content on their own devices. Browsers have always allowed customisation, from disabling images to blocking JavaScript.

The web's technical standards explicitly accommodate user preferences, including mechanisms for overriding publisher styles. Springer's argument challenges this foundation by claiming that any deviation from publisher-intended display constitutes copyright theft.

If successful, it would grant content creators unprecedented control over user experience, essentially criminalising basic accessibility features and personal preferences.

The Hamburg court now faces a choice that will echo far beyond Germany's borders. Whether they realise it or not, they're deciding not just the fate of ad blockers, but the future of user agency online.

My prediction? 

It seems highly unlikely the Hamburg court will rule in Springer's favour. The Federal Court is probably seeking closure on a legal ambiguity rather than signaling it suspects website code deserves copyright protection. Germany has historically been pro-consumer in situations like this.

The Action Replay II case, decided the same day, supports this interpretation. The German Federal Court was comfortable ruling that runtime manipulation doesn't constitute code modification when dealing with actual computer programs.

Even if the court were to rule that ad blockers infringe copyright, enforcing it would be another matter. Consider the music industry versus Napster.

Sit comfortable. It will likely take 1-2 years before the court issues a verdict.

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