In human history, there have been many instances where the word of cannibalism has come up. There were ancient rituals where the eating of body parts such as the hearts of enemies was supposed to give strength (in fact would transfer the strength and valor of the enemy to the person who was eating the heart), there would be human sacrifices to the gods where after the sacrifice, the body parts would be cooked. In more modern times, there were tribes on isolated islands that would indulge in cannibalism, and would catch and eat people who wandered onto the island.
However, the thought of cannibalism, especially when it is present in modern times, makes people feel cold and clammy, there is the nightmare that it may happen to them, that the weird person who lives in the house nearby and does not let people come in is actually a cannibal.
In recent times, Moscow saw cases where pieces of human bodies were found scattered around the city, and there were worries about a serial killer (link to article):
A man suspected to be behind the appearance of dismembered body parts across Moscow in recent weeks was arrested early Tuesday morning after half-eaten human innards were found in his home, police said.
Police found a stew made from a human liver in the fridge at the suspect's apartment in east Moscow. They believe the liver to be part of the same body as various dismembered body parts found scattered around Moscow in recent weeks.
The decapitated head of a middle-aged man was found in the Moskva River in the west of the city Wednesday.