A key insight from anonymization is that you need to consider how easy it is to join that dataset together with some other freely available or cheaply available

A key insight from anonymization is that you need to consider how easy it is to join that dataset together with some other freely available or cheaply available datasets. GP said the person spent $20 buying voter information. A moderate to big company will even prevent employees from joining data sets from different departments of the company, as a matter of policy.