Facebook has been fined €110m (£94m) by the EU for misleading officials over its takeover of WhatsApp in 2014.
The European Commission says Facebook knew it would be able to share data between Facebook and WhatsApp users' accounts, despite claims to the contrary.
When Facebook notified the Commission over the acquisition of WhatsApp in 2014, it said it would be unable to automatically link people's accounts.
However, in August 2016, WhatsApp announced updates to its terms of service, including the possibility of linking WhatsApp users' phone numbers with their Facebook identities.
The move prompted the Commission to launch an investigation.
The Commission found that, contrary to Facebook's statements in 2014 during the merger review process, the possibility of automatically matching Facebook and WhatsApp identities already existed, and that staff were aware of this.
Moreover, the Commission says Facebook was also aware of the importance of this factor in the Commission's assessment of the merger.