h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Rather disturbingly, Scotland has it's very own family of cannibals. Kind of like the Brady Bunch but with odd eating habits (I can't remember exactly what period in history we're talking about here so I'll have to be vague and say it was a long time ago).
Sawney Bean and his wife lived in a cave on a beach onthe coast of Scotland where they picked off passers by and picknickers. To add to the carnage they had several children, all of whom they introduced to a life of cannibalism. When they were finally caught, the authorities thought up particularly nasty deaths for them to suffer because the population of Scotland was so horrified at what they had done. I believe the entire family were put to death (but I could be wrong).
As a very small child I remember being totally terrified of the models of Sawney Bean and his family in Edinburgh Waxworks Museum's 'chamber of horrors' and the story kind of stuck with me.

see entry A1047926 for more on them.