Hmm, I wonder about this. Consider that company A requests and is granted access to some of your data - what's to stop them selling that data on to company B?

Hmm, I wonder about this. Consider that company A requests and is granted access to some of your data - what's to stop them selling that data on to company B? Regulation could form part of the solution, but I'm wondering if anything can be done from a technical standpoint.