 Silly String and similar products have been used by the military to detect tripwires for explosive booby traps.The string is sprayed over the suspected area, and if the string falls to the ground, no tripwires are present, since the string would catch on the tripwires (but is not heavy enough to activate the explosive).The use of aerosol string products has been banned in several places for various reasons, including cleanup and removal costs and fears of potential damage to house or vehicle paint.