Airline passenger security screening services, namely, an expedited screening initiative that enhances aviation security and expedites the travel experience by pre-screening individuals who volunteer to participate in the program; consultation services concerning homeland safety and security issues, namely, in the field of public safety, personal security, and physical security; conducting personal security clearance background investigations for preparation of identification cards; public security services in the nature of passenger, baggage, and/or freight screening in connection with all modes of national transportation, namely, commercial and general aviation, mass transit systems, freight and passenger rail, highways, pipelines and ports, to protect homeland security and ensure freedom of movement for people and commerce