Mark Zuckerberg and his management team have been reported to use personal data of Facebook users as bargaining chips while negotiating deals with various business partners.

According to NBC news, who have reportedly seen leaked evidence of questionable business tactics by Facebook leadership, users' information about friends, relationships and photos have all been used as pawns in order to get best deals from the likes of Amazon, as well as smaller start-up companies.

The large chunk of 4,000 pages of leaked Facebook documents — including emails, webchats, presentations, spreadsheets and meeting summaries — reportedly stem from a lawsuit filed by a small start-up Six4Three, which sued Facebook in 2015 over the giant's plans to cut off access for Six4Three to some types of user data. In turn, Facebook argued that it was merely considering different business routes.

© AP Photo / Andrew Harnik In this April 11, 2018 file photo, Facebook CEO Mark Zuckerberg pauses while testifying on Capitol Hill in Washington

The leaked evidence, covering the period of 2011-12015, is said to reveal Facebook's approach to users' data, contradictory to its public statements on data security and sharing with third parties.

In Amazon's case, Facebook reportedly showed the company extended lenience in providing access to user data. In turn, Facebook had Amazon buy ads on the social media platform, as well as partnering with it on the launch of its Fire smartphone.

According to reports, Facebook management allocated the users' data to app developers, considered "close" to CEO Mark Zuckerberg or partners who spent money on advertising on the social network. Some companies reportedly shared their data in exchange.

Facebook has dismissed the allegation it "cherry-picked" partners based on their ad spending or relationship with executives.

Facebook's history of securing its users privacy is far from pristine. In 2018, the tech giant was embroiled in a scandal, when it was revealed that a London-based political consultancy firm Cambridge Analytica used personal information of millions of users without their consent, with Facebook admitting to have been aware of the breach since 2015.

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