Big Pharma will pay huge money for this data. Imagine targeted ads based on your medical history. This was exactly the scenario discussed, solving the "who'll pay?" problem, when our corporate overlords were negotiating data sharing with Google Health and Microsoft HealthVault.

Fortunately, at the time, this exploitation of patient data wasn't permitted, so those efforts fizzled out.

I've been out of the game for a few years, so I don't know the current legal and regulatory landscape.