Kristin Archick, U.S.-EU Cooperation Against Terrorism (CRS Report RS22030) (May 21, 2012) (full-text).
Since September 11, 2001, cooperation between the United States and the European Union relating to counterterrorism activities has increased. Nevertheless, some challenges persist in fostering closer U.S.-EU counterterrorism and law enforcement cooperation. Among the most prominent are data privacy and data protection concerns. The EU considers the privacy of personal data a basic right and EU rules and regulations strive to keep personal data out of the hands of law enforcement as much as possible. The negotiation of several U.S.-EU information-sharing agreements, from those related to tracking terrorist financial data to sharing airline passenger information, have been complicated by ongoing EU concerns about whether the United States could guarantee a sufficient level of protection for European citizens' personal data.