> The claim was that Facebook is known to engage in that behavior while then also lying about it when questioned.
That is not how I read the parent.
Facebook asked for a phone number for 2FA (purpose).
Facebook then supplied that information for ad-targetting (definitely not what the user expects or agreed to).
There was nothing on the page when filling in the phone number that it might then be used for something other than 2FA. Just a general statement in their inhuman ToS that they can repurpose data.
That can very reasonably be construed that Facebook lied to the user - they weren't adequately informed. It certainly wouldn't be informed consent in most contexts.
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But! If we are to take the view of whether Facebook has said one thing while actively doing another... Then the Cambridge Analytica scandal had it's own moment of that.
> “Every piece of content that you share on Facebook you own,” he [Zuckerberg] testified. ”You have complete control over who sees it and how you share it.”
> Facebook’s view that the device makers are not outsiders lets the partners go even further, The Times found: They can obtain data about a user’s Facebook friends, even those who have denied Facebook permission to share information with any third parties.
So, Facebook's official position was that you control your data, and who has access to it - but they didn't view device makers as a third party, and thus any device maker could overrule a user's choice and see their data if they wished.
As to the scale of the information a device maker can access...
> After connecting to Facebook, the BlackBerry Hub app was able to retrieve detailed data on 556 of Mr. LaForgia's friends, including relationship status, religious and political leanings and events they planned to attend. Facebook has said that it cut off third parties' access to this type of information in 2015, but that it does not consider BlackBerry a third party in this case.