For some, they're the world's most venal perpetrators of cyber-terrorism. For others, they're the poster group for the latest evolution in political and social activism. They call themselves Anonymous - a collective of hackers whose substantial skills allow them entry into the most secured levels of computerized data. They exist in the shadows, but there are few across the globe who aren't aware of their exploits. The documentary How Hackers Changed the World seeks to unmask these digital outlaws, and explores the ways in which they can serve as both an advocate for the public good and a sinister threat to the world's security structures.