I was watching a program on Discovery about human sacrifices. They said these acts aren't carried out anymore, and yet in many countries around the world today, even in America, people are killed for seemingly ritualistic reasons on a regular basis.
It could be argued that the Death Penalty it a ritualistic killing. Even though it isn't carried out to appease fictional gods, its existence is still justified on the grounds that it's for the greater good of the community and country, to protect it from further "evils" by dissuading would-be killers from committing murder.
[Image: Hood Museum of Art, Aztec sacrifice mural via]