Related by context. Frequent words. (Click for all words.) 32 surveillance 29 Surveillance 27 biometrics 25 imaging 25 intrusion detection 24 surveillance cameras 24 interdiction 23 scanners 23 Cameras 23 cameras 21 CCTV 20 monitoring 20 video 20 videotapes 19 camera 19 videotaped 19 unmanned aerial vehicles 18 scanning 18 monitor 18 Security 18 GPS tracking 18 homeland security 18 undercover 18 remote sensing 18 patrols 18 footage 18 scanner 17 law enforcement 17 surveillance tapes 17 enforcement 17 security 17 detection 17 situational awareness 17 videotape 16 X ray machines 16 videotaping 16 FBI 16 plainclothes 16 sensors 15 satellite imagery 15 wiretaps 15 thermal imaging 15 FBI agents 15 CCTV cameras 14 vigilance 14 patrol 14 lookouts 14 wiretapping 14 covert 14 CCTV footage 13 oversight 13 plain clothes 13 body scanners 13 facial recognition 13 spy satellites 13 interrogations 13 electronic warfare 12 unmanned aircraft 12 patrolling 12 voyeurism 12 radars 12 detectors 12 fingerprinting 12 surreptitiously 11 safeguards 11 inspections 11 monitored 11 unmanned 11 inspection 11 audio recordings 10 apprehend 10 tracking 10 screening 10 detain 10 reconnaissance 9 interrogating 9 dragnet 9 Foreign Intelligence Surveillance 9 wiretap 9 eavesdropping 9 counterterrorism 8 spying 8 interrogation 8 counter terrorism 8 radar 8 manhunt 8 supervision 7 countermeasures 7 eavesdrop 7 massive manhunt 7 antiterrorism 6 arrest 6 suspects 6 suspect 4 night vision goggles 4 snoop 3 snooping 2 airborne 1 quarantine 1 bugging 0 spy