International flight-paths of non-military aircraft can involve over-flights of sovereign land or sea territories and transit through or near foreign airspace. Aircraft may be harassed by local airforce, by buzzing or other threatening behaviour and communications, or by actually being fired upon. Foreign ground-controls may also threaten or withhold cooperation or assistance. Harassment may lead to an unjustified attack with casualties or fatalities. In some countries like the USA where there is considerable private aviation, small planes may be harassed by irresponsible private aviators, for entertainment, and private planes may be harassed by military aircraft if near bases or sensitive locations.