‘Big Data’ is of the moment. According to IBM, we’re creating 2.5 quintillion bytes of data every day. The data itself is everything from the songs you’ve listened to and holiday snaps to medical records and websites visited. There are concerns about the corporations who store reams of information about us. ISPs, Google, Apple and network providers all collect information about us. Governments too are interested in big data. There are concerns that this all-encompassing surveillance has implications for our privacy. Yet Big Data can also make big inroads in helping researchers cure disease. Can big data change the world and if so, who do we trust with ours? Speakers in this thrilling Battle of Ideas debate raise the stakes.