Facebook CEO Mark Zuckerberg has hit back at a UK parliamentary committee after confidential emails between senior executives were published by a fake news inquiry.
The Digital, Culture, Media and Sport (DCMS) Committee on Wednesday accused Facebook of cutting deals with some app developers to give them more access to data, while icing out others that it viewed as potential rivals.
The confidential documents were brought to light by US software company Six4Three, which were gathered as part of a legal case against the social network.
A 250-page cache by the committee set out a number of key issues, including the company's handling of user data and details of how it provided some companies with access to data on users' friends despite changes in 2015 to end such practices.
Internal emails between chief executive Mr Zuckerberg and vice president Justin Osofsky dating back to January 24, 2013, show that the Facebook co-founder green-lit removing some rivals' access to the social network, meaning Twitter could no longer allow people to find friends on its Vine video app.
Facebook said the documents are misleading and that the information they contain is "only part of the story,” adding: “Like any business, we had many internal conversations about the various ways we could build a sustainable business model for our platform.
“But the facts are clear: We’ve never sold people’s data.”
In a Facebook post, Mr Zuckerberg also sought to put the documents into context, saying: “Of course, we don’t let everyone develop on our platform.
"We blocked a lot of sketchy apps. We also didn't allow developers to use our platform to replicate our functionality or grow their services virally in a way that creates little value for people on Facebook.
“I understand there is a lot of scrutiny on how we run our systems. That's healthy given the vast number of people who use our services around the world, and it is right that we are constantly asked to explain what we do.
“But it's also important that the coverage of what we do -- including the explanation of these internal documents -- doesn't misrepresent our actions or motives."
The UK committee seized the documents from app developer Six4Three, maker of a now-defunct bikini-picture search app.
Six4Three acquired the files as part of a US lawsuit that accuses Facebook of deceptive, anti-competitive business practices. The documents remain under court seal in the US.
In a summary of key issues pertaining to the documents, the committee said Facebook "whitelisted," or made exceptions for, companies such as Airbnb and Netflix, giving them continued access to users' "friends" even after the tech giant announced changes in 2015 to end the practice.
"Facebook has clearly entered into whitelisting agreements with certain companies, which meant that after the platform changes in 2014/15 they maintained full access to friend’s data," the committee said.
"It is not clear that there was any user consent for this, nor how Facebook decided which companies should be whitelisted or not."
The documents "raise important questions about how Facebook treats users' data, their policies for working with app developers, and how they exercise their dominant position in the social media market," said committee chair Damian Collins.
"We don't feel we have had straight answers from Facebook on these important issues, which is why we are releasing the documents," he added.
The cache includes emails from Mr Zuckerberg and other key members of his staff.
The emails show the CEO and other executives scheming to leverage user data to favour companies not considered to be threats and to identify potential acquisitions.
Mr Collins also alleges "that increasing revenues from major app developers was one of the key drivers behind the Platform 3.0 changes at Facebook" in 2015, and that "the idea of linking access to friends data to the financial value of the developers' relationship with Facebook is a recurring feature".
A statement from Facebook said: "As we've said many times, the documents Six4Three gathered for their baseless case are only part of the story and are presented in a way that is very misleading without additional context.
"We stand by the platform changes we made in 2015 to stop a person from sharing their friends' data with developers.
"Like any business, we had many internal conversations about the various ways we could build a sustainable business model for our platform. But the facts are clear: we've never sold people's data."
In 2015, Facebook changed its developer API settings in order to stop developers from seeing data from friends of users who had downloaded their apps.
It was this feature that was exploited to harvest data as part of the Cambridge Analytica scandal.