Terrorism 68 Prevention 65 Law and legislation 61 National security 55 History 40 Civil rights 39 Government policy 32 Intelligence service 28 Electronic surveillance 25 Privacy, Right of 20 War on Terrorism, 2001-2009 15 Finance 11 HISTORY 10 Management 10 Foreign relations 9 General 9 Law enforcement 9 Mathematics 9 Cryptography 8 Diplomatic relations 7 Disclosure of information 7 Evaluation 7 Life Sciences 7 Noncitizens 7 Wiretapping 7 World War, 1939-1945 7 Life sciences 6 Medicine 6 Money laundering 6 Terrorists 6