Related by context. Frequent words. (Click for all words.) 36 surveillance 32 Surveillance 31 security 31 Security 30 surveillance cameras 28 cameras 28 intrusion detection 27 imaging 27 biometrics 26 remote sensing 26 monitoring 25 satellite imagery 25 spy satellites 25 X ray machines 25 CCTV 25 Cameras 24 scanners 24 wiretapping 23 facial recognition 23 counter terrorism 23 camera 22 unmanned aerial vehicles 22 safeguards 22 CCTV cameras 22 antiterrorism 22 interdiction 22 electronic warfare 21 counterterrorism 21 thermal imaging 21 unmanned aircraft 21 scanning 20 detection 20 situational awareness 20 monitor 20 homeland security 20 eavesdropping 20 radars 20 GPS tracking 19 scanner 19 unmanned 18 covert 18 video 18 sensors 17 enforcement 17 reconnaissance 17 law enforcement 17 detectors 16 wiretaps 16 Foreign Intelligence Surveillance 16 FBI 16 countermeasures 15 spying 15 night vision goggles 15 inspections 15 wiretap 15 monitored 15 inspection 14 body scanners 14 detain 13 tracking 13 plainclothes 13 radar 13 eavesdrop 13 vigilance 12 fingerprinting 12 apprehend 12 spy 12 oversight 11 interrogations 11 dragnet 11 plain clothes 11 footage 10 surveillance tapes 10 audio recordings 9 patrols 9 supervision 9 snooping 9 patrolling 8 snoop 8 airborne 8 quarantine 8 screening 8 suspects 8 interrogation 7 interrogating 6 videotapes 6 lookouts 6 undercover 6 voyeurism 6 patrol 6 bugging 5 manhunt 4 CCTV footage 4 FBI agents 4 videotape 4 videotaping 2 surreptitiously 2 arrest 0 videotaped 0 massive manhunt 0 suspect