The British Board of Film Classification has passed Sega's MadWorld with an "18" rating. The Wii title received the classification for containing "very strong, stylized, bloody violence." Sega has been working with both the BBFC and the United States' ESRB to avoid the respective regions' "kiss of death." The publisher contributed builds at various times for feedback on what needed to be changed to dodge being "unclassified" in the Britain and receiving an "AO" rating in the States.
We're unaware if Sega has also been showing builds to Australia's conservative OFLC. If any region is going to "ban" MadWorld, it'll be the Aussies, due to the region's lack of an R18+ rating for games.