Intelligence gathering is in a state of flux. Enabled by massive computing power, new modes of communications analysis now touch the lives of citizens around the globe - not just those considered suspicious or threatening. Big Data Surveillance and Security Intelligence reveals the profound shift to big data practices that security agencies have made in recent years, as the increasing volume of information challenges traditional ways of gathering intelligence. In this astute collection, leading academics, civil society experts, and regulators debate the pressing questions this trend raises about civil liberties, human rights, and privacy protection in Canada.