Security measures Terrorism Prevention 132 National security 26 Transportation 24 Aeronautics, Commercial 23 Government policy 22 more ... Harbors 19 Airports 17 Rules and practice 16 Evaluation 15 Airline passenger security screening 11 Marine terminals 11 Safety measures 10 Shipping 10 Infrastructure (Economics) 9 Ports of entry 9 Effect of terrorism on 8 Public buildings 8 Computer networks 7 Computer security 7 Management 7 Passenger traffic 7 Bioterrorism 6 Planning 6 Economic aspects 5 Emergency management 5 Identification 5 Industries 5 International cooperation 5 less ...