In a landmark case that may serve as the bellwether for how the European Union approaches major tech companies going forward, Facebook (FB  ) lost its appeal in Germany's Federal Court of Justice. The decision found Facebook in violation of German antitrust laws and upholds an earlier decision by the German Federal Cartel Office.

In February of last year, the Federal Cartel Office found that Facebook's business model violated German antitrust regulations. According to the Cartel Office, Facebook had been abusing its dominant position by coercing users into surrendering their data through an "all or nothing" choice. The choice was either allowing Facebook to collect user data, or not using any Facebook products at all. The office also found that Facebook was illegally combining data harvested through its flagship site with data from its acquired products, such as Instagram and WhatsApp, as well as harvesting data from non-affiliated sites through plugins such as like and share buttons.

With the decision of the higher German court, Facebook is now required to allow users to block it from harvesting their data and combining it with data from other websites. The top court decision laid out a timeline for Facebook to come to comply with the decision, giving the social media company four months to plan out implementation, and another ten months to implement said plan.

"There are no serious doubts about Facebook's dominant position in the German social media network market, or that Facebook is abusing its dominant position with the terms of use prohibited by the Federal Cartel Office," said the court decision.

The decision may not be entirely final, however. The lower German courts must still make a final decision, and it's entirely possible that courts could side with Facebook, likely setting off a second appeal process and another higher court decision. However, the strongly worded decision by the higher German court may more than likely cause the lower court to affirm the judgment.

Facebook is no stranger to antitrust issues, finding itself under investigation by the United States Congress, the Federal Trade Commission, and the Department of Justice. Other tech companies are also under intensive antitrust investigations; recently, Apple (APPL  ) found itself under investigation by the European Commission for anticompetitive behavior, while Alphabet (GOOGL  ), Amazon (AMZN  ), as well as Apple, are similarly under investigation by U.S. authorities alongside Facebook.