Imagine if this was actually created by the NSA (I mean, naming it Prism seems too obvious to be true), and we're all just falling into it's aesthetically-pleasing honeytrap.
Or suppose the company that built it were party to a data-sharing arrangement for the purposes of marketing. This is a weakness of SaaS in general. I remember not too long ago when ZoneAlarm would ask me if I wanted application X to access the internet, usually I'd think "WTF for?" or "I'll update manually, TYVM."