The data that we record daily about ourselves through our cell phones, credit card purchases, emails, social media postings, etc., helps us connect with each other and improve our life quality. But we do not own nor control most of this data. I will discuss the good and the bad in this powerful information technology, including a number of cases – some inspiring, some terrifying – and what we can do as citizens to obtain the promise of big data while mitigating some of the worst problems. Among other things, I will trace problems with the release of "anonymized" data that is later "deanonymized".