Well, what about:
- Phone companies who know every single call you make, and already do sell that information to marketers and other companies.
- Credit card companies who know every single purchase you make and have your full name and address and phone and social security number (rather than just an email address) and already do sell that information to marketers and other companies.
- Banks who have all of your financial information and could at any minute release it to other companies, or have the security compromised.
- The government who already has all of this information and loses laptops with social security numbers and other really sensitive information at staggering rates - among other, far scarier things it does regularly.