ABSTRACT
This chapter demonstrates the growth in the creation of data-sharing tools used for security purposes at the European Union (EU) level. This expansion includes systems that initially fell under the scope of border management and commercial policies. The chapter examines whether these measures are actually effective in preventing and detecting crimes, or whether they are rather weak in practice. It explores the successes and shortcomings that the EU is encountering in the establishment of harmonised data protection rules in the field of law enforcement. The EU nonetheless found a way to legislate on criminal matters by enacting either intergovernmental measures within the scope of the former third pillar or directives as part of the former first pillar. In essence, the idea of co-operating against terrorism and cross-border crimes became an EU priority with the Treaty of Maastricht. Today mutual recognition applies to other legal areas that are not harmonised at the EU level, such as criminal law.
