If you did see one of these anti-riot vehicles at the 2008 North American International Auto Show, it's probably time to run. Police all around the world utilize special vehicles in situations where (at least, ideally) large crowds are getting violently out of control. These monsters are equipped with all kinds of deterrents against force, such as high-pressure water cannons, gas canister launchers, steel plows and bean bag launchers. When things get even worse, some countries even have vehicles fitted with space for soldiers and guns. Due to funding constraints in some places, some police forces take existing vehicles and refit them, such as the PTU from Singapore, which used to be a bus.
In the gallery below, from left to right: the KRAZ AVC-30 from Ukraine, "Avalanche" for the Russian special police, a Russian BRDM used by Czech Police, the PTU from Singapore, and a heavy-duty Slovakian model that looks a bit like a Russian BMP.