It's to do with the downright sinister German childrens book Struwwelpeter, in which a scissor wielding man cuts off a childs thumbs because he sucks them too much. Quote from wikipedia "In Die Geschichte vom Daumenlutscher (The Story of Little Suck-a-Thumb), a mother warns her son not to suck his thumbs. However, when she goes out of the house he resumes his thumb sucking, until a roving tailor appears and cuts off his thumbs with giant scissors." http://en.wikipedia.org/wiki/Struwwelpeter
It's to do with the downright sinister German childrens book Struwwelpeter, in which a scissor wielding man cuts off a childs thumbs because he sucks them too much. Quote from wikipedia "In Die Geschichte vom Daumenlutscher (The Story of Little Suck-a-Thumb), a mother warns her son not to suck his thumbs. However, when she goes out of the house he resumes his thumb sucking, until a roving tailor appears and cuts off his thumbs with giant scissors." http://en.wikipedia.org/wiki/Struwwelpeter