WhatsApp Messenger, the immensely popular cross-platform instant messenger service for smartphones, which enables users to stay connected, send media files, and group chat has encountered some heavy weather.  The messenger app has landed in hot water for breaching international privacy laws due to the manner in which it handles Address Book data, per Canadian and Dutch data authorities.

"WhatsApp, one of the most popular apps in the world, contravenes international privacy laws because it forces users to provide access to their entire address book, Canadian and Dutch data protection authorities said," reported Reuters.

WhatsApp is estimated to have more than 300 million users globally, and ranks as one of the top five best-selling apps in the world.  The instant messenger app has been produced by Canada-based WhatsApp Inc. and provides users with a free Internet alternative to text messaging.

The news comes in wake of increased criticism of social platforms like Facebook and Instagram, over the sharing and storage of personal information.

Per a Reuters report, the Office of the Privacy Commissioner of Canada (OPC) and the Dutch Data Protection Authority, released a joint report on Jan. 28, which disclosed that the app flouted privacy laws since "users have to provide access to all phone numbers in their address book, including both users and non-users of the app."

"This lack of choice contravenes (Canadian and Dutch) privacy law. Both users and non-users should have control over their personal data and users must be able to freely decide what contact details they wish to share with WhatsApp," said Jacob Kohnstamm, chairman of the Dutch Data Protection Authority.

The investigation revealed that WhatsApp kept the mobile numbers of non-users, violating privacy laws. The investigators disclosed that WhatsApp committed to bringing changes to protect a user's privacy. In Sept. 2012, the Canadian company introduced encryption for the messaging service to tackle the concerns raised by investigators. The service will apparently allow the manual update of contacts to counter the privacy breach issue.

WhatsApp Inc. is yet to comment on the issue. The Dutch agency averred that it would continue to monitor WhatsApp and may even impose penalties if the service continued to breach privacy laws.