Drinking Blood
Some rituals require the drinking of blood, does that mean the person who drinks it can be considered a cannibal?
In my belief the drinking of blood is one of the greatest taboos.
It is one of the substances that holds the greatest magical signatures for a person, and should never be disrespected.
As for it being cannibalism, it depends how you classify the difference between body fluid and flesh.
Not a pleasant subject really. As I said, one of the greatest psychological and spiritual taboos.