Yes. I know of one story where this person I knew was working in the chicken barns, and he saw this one chicken in this cage with this dead chicken. He removed the dead chicken and figured the live one needed a friend so he put another chicken in with it. Well, he quickly discovered why the other chicken was dead... That one chicken went right after the new one, immediately pecking it in the same spot the dead chicken had been injured in until it killed the new chicken and had gotten to its intestines.
Then there are some people who feed their chickens cooked chicken. I'm not one who does that, and thankfully my only cannibalistic behaviors of my chickens are egg eating and feather plucking. Chickens are some of the more cannibalistic creatures out there, so you do have to be mindful of them, especially if there's blood on any of your girls. (If they see blood, they'll peck at it, even to the point of pecking them to death.)