I have heard is one that my father thought up after the D.C. snipers created havoc in 2002. The basic idea is to arm twenty terrorists with rifles and cars, and arrange to have them begin shooting randomly at pre-set times all across the country. Big cities, little cities, suburbs, etc. Have them move around a lot. No one will know when and where the next attack will be. The chaos would be unbelievable, especially considering how few resources it would require of the terrorists.
