A commercial court in Brussels today ruled that Facebook must stop using cookies to track users when they aren't logged in, reports The Wall Street Journal. The social networking company now has 48 hours to comply, or it will face a daily fine of €250,000. However, the company has vowed to appeal the decision on the basis of user security.

"We’ve used the data cookie for more than five years to keep Facebook secure for 1.5 billion people around the world," a Facebook spokesperson told the Journal. "We will appeal this decision and are working to minimize any disruption to people’s access to Facebook in Belgium."

Today's decision comes months after the Belgian Privacy Committee released a report showing how Facebook's tracking cookies identify users clicking Like buttons across the web, even if those users explicitly logged out or deactivated their accounts. According to the Commission, that violates European law requiring companies to allow users to opt out of online tracking.

Facebook, for its part, has long disputed the report's findings. According to the company, cookies allow it to identify computers that would be otherwise be used to hack into users' accounts. Any data that's collected is deleted after 10 days. For now, the fight is far from over.