I'm having trouble coming up with a legal theory where users could sue the 3rd party acquirer under contract law. As an alternative, how about IP law? The user

I'm having trouble coming up with a legal theory where users could sue the 3rd party acquirer under contract law. As an alternative, how about IP law? The user could own the information, and grant a nonexclusive license to hunch.com to use it strictly for running hunch.com and no other purpose. If hunch.com later sold that information to a 3rd party, one could go to the 3rd party and get it back, because the property was never hunch's to give.