Principles to be weighed when deciding whether a function belongs at the State or Federal level include dispersal of power, accountability, participation, diversity, competition, experimentation, and containment in regard to disposal of power. For example, States can recognize polygraph abuse by private employers as well as the Federal Government, especially since the rights of the citizens to whom they are immediately accountable are at stake. Seventy percent of the States have already provided polygraph legislation. Polygraph use should be evaluated by the States in terms of other investigative alternatives and consumer, employee, and employer interests. The test is useful in screening airport security personnel involved with nuclear materials and truck drivers who transport hazardous materials. States that have regulated polygraph testing have done so in diverse ways, allowing for alternatives according to citizen opposition or support. Nineteen States regulate employer use of the test, some completely ban it, others prohibit it to be an employment requirement, and six States regulate polygraph examiners.