Mark Zuckerberg shared private user data with Facebook 'friends', leaked documents reveal

Internal emails suggest companies were incentivised to share information with social media giant

Facebook co-founder Mark Zuckerberg used people's data as a weapon against rivals of the social network (AFP/Getty Images)

Facebook CEO Mark Zuckerberg gave access to sensitive user data to dozens of app developer friends, according to thousands of leaked documents.

Zuckerberg reportedly used the data as a reward to third party companies and developers who either had a favourable relationship with company executives or spent considerable amounts on ads.

Companies were also incentivised to share their data with Facebook, while those that did not were shut out and denied access.

These methods helped to consolidate Facebook’s position as the leading social network platform between 2011 and 2015, the leak suggests.

The trove of documents obtained by investigative journalist Duncan Campbell included emails, presentations, meeting summaries and internal webchats from within the company.

Around 4,000 pages shared with NBC News, Computer Weekly and Germany’s Süddeutsche Zeitung newspaper revealed the extent of the data sharing collaborations.

Facebook did not immediately respond to a request for comment from The Independent but a statement provided to NBC News said the documents were authentic but misleading.

“The set of documents, by design, tells only one side of the story and omits important context,” said Paul Grewal, vice president and deputy general counsel at Facebook.

“We will stand by the platform changes we made in 2014/2015 to prevent people from sharing their friend’s information with developers... The facts are clear: we’ve never sold people’s data.”

Facebook did not provide additional documents to support its claim the documents had been cherry picked.