The amount of data in the world is massive. It is so massive that foreign governments are taking this information, from a variety of sources, and creating profiles of important figures in society. Companies are collecting information without your permission to improve sales and then keeping it in an unsecured way that leads to data theft.
We are weak human beings sometimes. If we have a love for some product we have a hard time not buying it. Yet if a company puts lots of ads in front of us targeting our interests we may make even more purchases. Data and information can be useful for marketing but also can be destructive.
One of the biggest problems is that people don't know how much data is really out there. Companies collect this data and then use it for many types of purposes. Even if they were only using this information for sales it is hackers and others that collect this information for devious purposes.
Let's say that someone really wanted information about a politician or notable figure. They could hack their credit cards, hack social security, etc... If they also get access to your purchases they would be able to know just everything about you. Perhaps they know more about you then you know about yourself at some deep psychological level!
As of yet we don't know of hackers with that capacity. However, we do know they sell this data and someone who has the money and time could collect and dump that into a cross referencing data analysis tool and then start picking out your information. While this may not be important to you it may be important to others.
Disclosures on what companies are collecting and how long they keep this information is important for improving the overall privacy of that information.