With many companies these days, you are the product they are ultimately selling. Facebook is probably the worst offender, but Google and other companies are the same way. Their goal is to sell you to advertisers however they can. That means your privacy is always suspect and frequently abused.
This is one of the reasons I like Apple. Here’s an announcement they just made on their new privacy site:
They actively work to make your personal data impossible for them to see, because they don’t need to. Their product is the hardware, not you. You’ll likely hear people saying they don’t trust the new Pay, but it’s probably the safest way you can use your credit card. The card information is secured on the phone and never leaves it, no one can get to it (not even Apple), and the information that passes to the reader is not even your real card number. The purchase information is also never transmitted to Apple, because you are not their product–they don’t need or want that information. iMessages are encrypted from point to point so that Apple can’t see them, the fingerprint data (not even the actual fingerprint) for the fingerprint sensor is stored in a place that can’t be accessed, even by Apple, etc. There’s a lot of FUD out there, but just follow the money. Where does a company’s majority income come from? That will tell you what is really being sold.