Privacy and data ownership. The privacy of data is another huge concern, and one that increases in the context of Big Data. For electronic health records, there are strict laws governing what data can be revealed in different contexts. For other data, regulations, particularly in the U.S., are less forceful. However, there is great public fear regarding the inappropriate use of personal data, particularly through linking of data from multiple sources. Managing privacy effectively is both a technical and a sociological problem, which must be addressed jointly from both perspectives to realize the promise of Big Data.