A Viennese court's ruling on Monday upped the challenge to Facebook on how the social media site uses a cookie to track data.

In a November court proceeding in Belgium, Facebook was ordered to stop tracking European web users via a cookie named 'datr,' embedded in the code for its "Like" button capable of siphoning personal data even from non-Facebook users.

The technology confronts EU data-protection laws that grants "informed consent" to users and forbids the processing of personal data that is "excessive in relation to the purposes pursued," Brendan van Alsenoy, a legal researcher, told ZDNet.

In a Dec. 9 blog post, Facebook CSO Alex Stamos said the firm would comply with the court's ruling but argued that the cookie is a security precaution that "helps us determine when people are viewing Facebook pages for legitimate reasons or are trying instead to copy large amounts of other people's data...without permission."