Facebook's special arrangements with some of the world's largest technology companies have been detailed in the social media giant's documents obtained by The New York Times.

The company's records describe data-sharing deals that benefited dozens of other companies by utilising personal data from Facebook users.

Facebook was "effectively exempting those business partners from its usual privacy rules", according to internal records and interviews, the NYTreported on Wednesday.

The records, generated in 2017 by the company's internal system for tracking partnerships, provide a picture of Facebook's data-sharing practices.

They also underscore how personal data has become, NYT reported, "the most prized commodity of the digital age, traded on a vast scale by some of the most powerful companies in Silicon Valley and beyond".

The personal information of Facebook's 2.2 billion users was unknowingly put to work for Miscrosoft's Bing search engine, for example, which could see the names of nearly all Facebook user's friends without consent.

Facebook also gave Netflix and Spotify the ability to read people's private messages. Amazon was permitted to get a users' name and contact details through their friends.

That was despite statement the company made publicly saying it stopped that kind of behaviour years earlier.

A netflix spokesperson says over the years they have tried various ways to make Netflix more social.

"One example of this was a feature we launched in 2014 that enabled members to recommend TV shows and movies to their Facebook friends via Messenger or Netflix.

"It was never that popular so we shut the feature down in 2015.

"At no time did we access people's private messages on Facebook, or ask for the ability to do so."

The investigation by The New York Times was based on hundreds of pages of internal Facebook documents and interviews with about 50 former employees of Facebook and its partners and it found the marketplace for that users' data is even bigger than many consumers suspected.

-Stuff