Big data equals Big Brother? The big data explosion forces us to confront the privacy implications of this wide-ranging societal change. In this session, we will talk about privacy-related efforts: both in Microsoft Research and in academia. What does privacy means in the context of always-on sensors such as Kinect? What happens to parents and teenagers living in Internet-connected homes? How do we sanitize documents on a large scale? How can we quantify privacy and privacy loss? These topics and others will be discussed with the goal of creating shared understanding as well as collaborative research opportunities.