Facebook has been accused of striking secret deals with app developers to allow them access to user data and mining user devices to information about third-party app use.
MP Damian Collins who is chairing the DCMS Committee has raised several concerns about the social media company.
It is alleged that Facebook allowed some companies to maintain more access to users' friends lists after it changed its rules in 2015.
Also of concern was Facebook's data collection on Android, where it kept a record of calls and text messages to allow it to make suggestions to users about what contacts should appear first in the messenger app.
The company is also said to have used a third-party company called Onavo to monitor apps installed on devices. The purpose, according to the report, was to determine apps that competed with Facebook or which might be ideal for acquisition by the firm.
The committee also noted that in an email exchange between senior executive Justin Osofsk and Mark Zuckerberg the two discussed Twitter's shortform video platform Vine. The service had been using Facebook to help users find friends to follow or invite.
In the exchange Osofsk suggested pulling Twitter's API access to Facebook friends. Zuckerberg agreed to the idea. Vine later failed, but it's unclear if this action by Facebook played any part in that.
Facebook has reacted to the release with some anger, posting a statement about the documents and explaining its stance on each point.
The company strongly denied many of the claims. It was especially forceful on the subject of sharing extra friends data with some developers but not others. The company said that this was only done to help developers transition their apps to the new rules to prevent disruption.
Facebook said that users were asked to opt-in to sharing data about their call and text logs. It said that it needed this to be constantly updated because old data was no use for ranking contacts in messenger.
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Interestingly Facebook didn't deny using third-party apps to gather data on phone use. However it did say that customers can opt-out and the company has been clear about how it uses that data.
The company also claims that the emails leaked do not present a complete picture of the company's practices.