Given away. It is BS to say the use of personal information as currency is "clearly stated" in the terms of service. The Big Five make ZERO effort to ensure users have read and understand how they are paying for the services they offer for "free". They write long form legalese, and they present a little Web link labelled " as have read the terms of service" next to a checkbox in the sign up and there is no mechanism whatsoever to ensure a person has read it.
It is partly our fault for lying by checking the box without following the link, but companies do the absolute minimum required to inform users. They in fact go out of their way to hide their terms.
It's as if a store leaves their stuff on a shelf, without price tags, but a sign saying "take and enjoy!" with fine print saying "you agree to the terms of the agreement available at the customer service desk" underneath. Then when they get home they discover their bank account cleaned out. They go back to the store and they say sorry you agreed to the terms by taking the stuff. It's not our fault you didn't go to customer service desk to get the 5 page agreement stating we have full access to your bank account and can take whatever you want and that we do not take returns.
The point is they are using their services as bait, and their behaviour wouldn't be tolerated when the currency is cash and the product is tangible. Society does not yet appear to value personal information like cash. People give it freely, corporations leverage it however they please without regard to consequences and governments forcefully take whatever they want to further their agendas. Perhaps one day we will live in a Roddenberry style economy without cash and the new currency will be information and it will be valued and respected accordingly, but we are far from that point right now.