Human Sacrifice is a common theme in many forms of fiction as well as folklore, mythology and theological tales - much like cannibalism the practice of human sacrifice was once acceptable in some cultures but became increasingly demonized over the course of time to the point that it is now widely used as a symbol of evil and depravity.
Human Sacrifice is commonly believed to be practiced by Satanists and other cults associated with "devil-worship" and although some fringe groups have committed such crimes they are in the extreme minority and in religions where sacrifice is required almost all mainstream practitioners limit it to animals.
Human Sacrifice was extremely common in Aztec societies but has become extremely blurred over time, often envisioned as vicious and bloodthirsty killers the truth of the Aztecs and their belief system has likely been lost to time - though their are definitely depictions of Aztec art that shows what many in the modern world would consider massacres.
The Ancient Norse perfomed a gruesome sacrifice to Christians known as "blood eagle" in which they would cut open the victim and spread the ribs like the wings of an eagle: although clearly ritualistic it is debatable how much of this was done for religious reasons and how much was done as a means of striking fear into their enemies.
The idea of Human Sacrifice is as old as the concept of gods, demons and spirits - to many the sacrifice of human life is totally at odds with what we now see as civilized society and for this reason it has become a common tool in fiction for those of an evil mind.
Common ideas in fiction of Human Sacrifice include tossing people into volcanoes (as almost happened in Madgascar 2), offering people to gigantic monsters (as happened in King Kong) and burning people alive (as happened in the Wicker Man).