A recent ruling from Germany’s Federal Supreme Court (BGH) has revived a legal battle over whether browser-based ad blockers infringe copyright, raising fears about a potential ban of the tools in the country.

The case stems from online media company Axel Springer’s lawsuit against Eyeo — the maker of the popular Adblock Plus browser extension.

Axel Springer says that ad blockers threaten its revenue generation model and frames website execution inside web browsers as a copyright violation.