This book critically assesses legal frameworks involving the bulk processing of personal data, initially collected by the private sector, to predict and prevent crime through advanced profiling technologies. In the European Union (EU), mass data surveillance currently engages three sectors: electronic communications (under the e-Privacy Directive), air travelling (under the Passenger Name Records Directive), and finance (under the Anti-Money Laundering Directive), and increasingly intersects with the deployment of predictive policing techniques. The book questions the legitimacy and impact of these frameworks in light of the EU's powers to provide security while safeguarding fundamental rights, particularly privacy, data protection, effective remedy, fair trial, and presumption of innocence.Focusing on the security shift towards forestalling crime before it occurs, the book identifies its distinct characteristics, such as the blurred lines between the public and private sector actors, and interrogates whether the legal bases and traditional theories on security can account for it. The book further explores the challenges these pre-crime practices pose, including their questionable effectiveness and the ambiguous application of human rights safeguards in situations where no crime has been committed, yet individuals face consequences as a result of deploying predictive analytics on mass amounts of commercially collected personal data. In examining the interference with several fundamental rights, the book also highlights aspects neglected by the jurisprudence of the Court of Justice of the European Union and the European Court of Human Rights, such as the expansive nature and the collective and cumulative effects of these frameworks.