Call of Duty: Modern Warfare will bring back killstreak rewards in multiplayer, publisher Activision has confirmed just ahead of the game's full multiplayer reveal on August 1. However, one of the killstreak options has caused some controversy. The three killstreak rewards announced so far are a juggernaut care package, an armored assault vehicle, and the chemical weapon white phosphorus, and it's that last one that has proven contentious.
In past calls of duty, all three characters have appeared in one form or another: Juggernauts and light armored vehicles are widely used in modern warfare subseries. White phosphorus has been used as a tactical grenade in the Black Ops series -- "causing a small amount of damage when detonated" -- but this "bonus" weapon frame makes a difference.
In real life, the use of white phosphorus on civilians and civilian areas - also known as "willypete" - violates the Geneva conventions and is therefore classified as a war crime. Some modern war multiplayer maps take place in civilian areas, although there are no civilian characters.
It's unclear whether multiplayer will treat white phosphorus as strictly as it sounds, just as story mode treats "mistakes." This is the root of some recent controversies.