To somehow introduce fire to an object or location (ie, unpopular government buildings) which are not intended to have fire on them. Typically done with a Molotov Cocktail or some other improvised incendiary device. It is usually the last method resorted to by rioters or serious troublemakers. These days firebombing has an unfortunate link in people's minds, usually with crazy people burning down clinics which perform abortions. Firebombing is also the last recourse of democracy, the means for the disgruntled public to strike back with the simplest tools available. Wherever there is unrest, there is firebombing. It doesn't matter where you are on Earth, chances are someone is considering a firebombing. This is more true for some places than others.
This can also refer to the firebomb itself, but firebombs are discussed more thoroughly in other nodes. One of the common concepts which accompanies the firebomb is the bomb-throwing anarchist, some young malcontent with a molotov in hand, angry with the world. See also: arson, The Anarchist's Cookbook.