Big Data (in service to the NSA) wants to be able to document what you do and when and where and with whom. All of the current databases that companies and public agencies maintain can now be tightly linked to get a pretty good profile of any individual.
But, these models of what people will do when you ask them to buy a DVD of Thor 2 or a suit from Brooks Brothers, are actually fairly dumb brute force computer algorithms that break down when certain types of problematic data are fed into them.
Hhhhmmm. Some thoughts below in the mind map. Click the image twice for a full expansion.