Instagram, the photo-sharing app now owned by Facebook, has risked upsetting many of its millions of users by implementing a new privacy policy that will allow the sharing of user data with its new parent and pave the way for targeted mobile advertising.

The updated privacy policy is due to come into force on 16 January and promises deeper integration with the social networking giant. Facebook completed its US$1 billion acquisition of Instagram in September.

“We may share user content and your information (including but not limited to, information from cookies, log files, device identifiers, location data, and usage data) with businesses that are legally part of the same group of companies that Instagram is part of, or that become part of that group,” Instagram said, referring to Facebook.

It later hints that the currently ad-free app is also set to be integrated into Facebook’s mobile advertising platform. “We may ask advertisers or other partners to serve ads or services to your devices, which may use cookies or similar technologies placed by us or the third party,” says the policy document.

Critics point to wording in the policy that appears to give Instagram the right to sell users’ photos without payment or notification. There are also appears to be no way for users to opt out of the new policy, prompting speculation that many could cancel their accounts prior to the policy coming into force.

Instagram recently angered users by preventing Twitter to embed images directly into tweets – another policy apparently linked to its acquisition by Facebook.