‘Big data security and the Snowden case’ looks at some of the security issues surrounding big data and the importance of encryption. Some of the problems facing big data systems include ensuring they actually work as intended, can be fixed when they break down, and are tamper-proof and accessible only to those with the correct authorization. Hacking and data theft have become the main problem facing big data. The hacks of Home Depot in 2014 and of Yahoo! in 2016 are described, as well as the Edward Snowden case, Wikileaks, TOR, and the Dark Web. If we want to make big data secure, encryption is vital.