Left 4 Dead 2's been refused classification in Australia. See here: that's what the "RC" means.
Why? We'll tell you why. Or rather, the OFLC'll tell you why, through the magic gateway that is Gamespot:
"The game contains realistic, frenetic and unrelenting violence which is inflicted upon "the Infected" who are living humans infected with a rabies-like virus that causes them to act violently" The ruling goes on to say that "However, it is the use of the "melee" weapons such as the crowbar, axe, chainsaw and Samurai sword which inflict the most damage. These close in attacks cause copious amounts of blood spray and splatter, decapitations and limb dismemberment as well as locational damage where contact is made to the enemy which may reveal skeletal bits and gore."
Yeah, you see: the "realistic, frenetic and unrelenting violence" is the reason it's awesome, Mr OFLC.
Australia doesn't allow games to be rated over "15+," which means anything that deserves an 18 gets effectively banned from sale.
Left 4 Dead releases in the civilised world in the coming months.