What are the ramifications of open cannibalism?
Solution 1:
I couldn't resist trying this perk. I didn't opt for it in Fallout 3, so I can only speak of New Vegas.
If you drag a body to the corner where no one can see you, there are no problems. You gain health, gain rads, and lose a little karma.
If you do it in the open (while [Detected]), everyone turns hostile against you. But they forget soon enough... if you leave the town and come back, all is good. It won't change how a faction thinks of you.
It's the same thing as stealing from or killing a random person. Take out a leader... and there are problems. But otherwise, no biggie.