• by Wendy Davis  @wendyndavis, December 19, 2017

Privacy regulators in France have ordered messaging service WhatsApp to stop sharing users' data with Facebook.

The move, announced this week by the chair of France's National Data Protection Commission, marks the latest in a series of actions by EU authorities stemming from Facebook's decision to mesh data with WhatsApp.

Last year, WhatsApp announced plans to share users' phone numbers and other information with Facebook. Facebook, which acquired WhatsApp in 2014, said it would draw on those numbers to make friend suggestions to WhatsApp users, and also send them ads, based on Facebook data. The company also will use phone numbers for other purposes, including analytics and fighting spam.

WhatsApp promised to let people opt out of receiving targeted ads (and receiving friend suggestions) based on phone numbers. But the company refused to allow people to avoid having their phone numbers shared with Facebook.

France's top privacy regulator said this week that WhatsApp's data transfers to Facebook violate the French Data Protection Act, writing that users didn't validly consent to share information about themselves. One reason for the decision was that WhatsApp users had to agree to WhatsApp's new terms in order to continue using the messaging service.

"This transfer does not provide adequate guarantees ... to preserve the interest or the fundamental freedoms of users since there is no mechanism whereby they can refuse it while continuing to use the application," the regulator's decision says.

Earlier this year, regulators in Europe's Article 29 Working Party raised a similar concern. The European Commission also fined Facebook $122 million for misleading officials about its ability to automatically combine data about its users with those of the messaging service WhatsApp.

Prior to merging with Facebook, WhatsApp was famous for its stringent privacy policies, including a promise to never share users' personally identifiable information for ad purposes.

The French authorities told WhatsApp to stop transferring data to Facebook within one month or risk sanctions.