Threat Modeling

Threat modeling for privacy issues is an emergent and important area. Much like security threats violate a required security property, privacy threats are where a required privacy property is violated. Defining privacy requirements is a delicate balancing act.  For example, an organization offering a service may want or even need a lot of information that the people using the service don’t want to provide.  People have very different perceptions of what privacy is, and what data is private, and those perceptions can change with time. (For example, someone leaving an abusive relationship should be newly sensitive to the value of location privacy, and perhaps consider their address private for the first time.) 

Question:  Are concerns over privacy is a waste?  In other words, if you are not doing anything criminal or illegal then you have nothing to hide.  What are you own person thoughts on privacy?