Earlier this year WhatsApp announced it was to start sharing data with Facebook. Now the EU's Data Protection advisory group (Article 29) has expressed its 'serious concern' about these changes. It is particularly concerned about the 'opt out' nature of the data collection process which, it claims, means that people had no way to consent. German regulators are also concerned that Facebook will collect contact data from users who aren't even on the social network.
The group has asked Facebook to reveal what data it is collecting.
WhatsApp has confirmed that "constructive conversations" have been held with EU authorities, even prior to the change in policy.