PARIS (Reuters) - Facebook's move to relax the privacy policy of WhatsApp, the world's most popular mobile messaging application, will be closely scrutinized, the chair of Europe's leading group of privacy regulators said on Monday.
WhatsApp, which counts more than a billion users globally, said on Thursday it would start sharing users' phone numbers with Facebook (NASDAQ:FB), helping it to target advertisements and friend recommendations across the social media network.
It said WhatsApp users could choose not to share their account information with Facebook.
"Each European authority will be following the changes made to WhatApp's privacy policy with great vigilance," CNIL, the French data protection commission, and the current chair of the G29 or Article 29 Working Party of European privacy regulators, said in a statement on behalf of the region-wide group.
"What is at stake is the control of individual users over their own data when they are combined by major Internet players."
The G29 is made up of representatives of the data protection authorities of each of Europe's 28-member states, the European Data Protection Supervisor and the European Commission.
Facebook paid more than $19 billion to acquire WhatsApp, an advertising-free service for sharing texts, pictures and videos with friends and acquaintances. At the time of the deal in 2014, WhatsApp founder Jan Koum vowed to protect data of its users and said the deal would not affect its privacy policy.
In response, Britain's data privacy regulator, the Information Commissioner's Office (ICO), said it was monitoring the changes to ensure that the new policy stays within data protection laws (http://reut.rs/2bwpIdX).
The French data protection authority is studying Facebook's response earlier this month to issues the regulator has raised over the company's handling of customer data for targeting advertising to the social network's members.
CNIL has yet to receive any specific complaints from citizens to the latest changes to WhatsApp privacy policies, it said.
By Monday several European media including France Info and Switzerland's Le Temps warned readers about the policy change and gave them tips on how to avoid letting WhatsApp handing over their phone number to Facebook.
A CNIL spokeswoman said WhatsApp's privacy policy was likely to be discussed at a planned G29 meeting at the end of the month attended by representatives of each European national privacy regulator.