Once thought of as a specialized browser function, ad blocks are now at the heart of an ongoing conflict between internet users and publishers. The battle between publishers seeking to maintain their economic model and users seeking freedom from invasive advertisements has now reached a critical point before Germany’s top court.
Ad blockers may eventually be outlawed in Germany after a case was revived by the Federal Supreme Court (BGH). The dispute concerns media behemoth Axel Springer and Eyeo, the Cologne-based business that makes Adblock Plus, one of the most widely used ad-blocking programs worldwide.
The Case
According to Axel Springer, the company behind well-known publications like Bild and Welt, websites are composed of code that qualifies as a protected computer program in addition to text and images. It further argues that when an ad blocker hides an advertisement, it is actually illegally interfering with the underlying code that builds a website inside a browser without permission. Eyeo, meanwhile, maintains that it is only letting people choose what they want to see.
Previously, a Hamburg lower court rejected this argument because it was not persuaded. Parts of the decision were overturned by the BGH on July 31, 2025, claiming that judges had not adequately considered whether browser code such as the Document Object Model (DOM) and CSS Object Model (CSSOM) are legally protected works and whether concealing advertisements amounted to improper tinkering.
“It is impossible to deny that the bytecode or code derived from it is protected as a computer program, and that the ad blocker violated the exclusive right thereto by altering or changing reproduction,” according to BGH’s statement (automatic translation).
For further technical examination, the matter is currently being returned to the lower courts in Hamburg.
The Significance of It
The ramifications are not limited to advertising. Any browser plugin that alters websites—from privacy filters to accessibility tools—may be deemed unlawful if courts adopt Springer’s position. Ad blockers may be affected, but so may programs that increase accessibility, fortify security, or stop online tracking.
The creator of the Firefox browser, Mozilla, has cautioned that this could lead to Germany becoming the first democratic nation to ban ad blockers, a move it claims would compromise internet privacy, innovation, and user freedom.
According to a statement from Mozilla’s Senior IP & Product Counsel Daniel Nazer, the decision might have a “chilling effect,” with browsers blocking functionalities and extension developers retreating to avoid legal action.
We fervently hope that Germany won’t follow China as the second country to outlaw ad blockers. This will drastically reduce consumers’ control over their online surroundings and may pave the way for similar limitations in other places. A precedent like this might fortify legal objections against any extensions that safeguard privacy, increase accessibility, or strengthen security, Nazer continued.
What Comes Next
Now that it has returned to Hamburg’s lower courts, the matter is far from complete, and more hearings might go on for years. Ad blockers are still allowed in Germany until then, though it’s unclear how long that will last.
