It's very likely that they sell that data to the US intelligence community.

One good example is Skype which they bought two years after rumors surfaced [1] that the NSA offered billions for solutions that can wiretap Skype calls. After they've bought it, they removed end to end encryption as well as the peer to peer system, sending all content over Microsoft servers.

It's a bit better if it's "only" shared with the US intelligence community instead of anyone who names a price for it, but obviously still not really good for privacy.

[1]: https://www.theregister.co.uk/2009/02/12/nsa_offers_billions...