Some years ago, in Colorado, if memory serves, this guy, Marvin Heemeyer, was pissed at his whole town over some zoning issue or such, and built this monstrosity. It is a Komatsu bulldozer with steel and concrete armor, multiple cameras protected by 3 inch thick bullet resistant plastic attached to two monitors, and firing ports. He had mounted a Barret M82 .50 caliber rifle in the rear, and had 5.56 rifles, a Ruger Mini-14 on the right and a FN FNC in the front.
Well, as crazy fuckers tend to do, this dude went on a rampage, tearing the whole town apart, especially the businesses of his hated enemies from the town council. Eventually, he got the killdozer (as it came to be known) stuck in the foundation of a building he had demolished and while the police waited for the Colorado National Guard to get there with anti-tank weapons, he shot himself in the head with his .357 magnum.