A primary school in Manchester, England, is testing a new method of checking out books - by using childrens' thumbprint scans serve as their identity to check out books: Children, 4, 'to be fingerprinted to borrow school books from library' http://www.telegraph.co.uk/education/educationnews/7771112/Children-as-young-as-4-to-be-fingerprinted-to-borrow-school-books.html.
The story says this comes after a plan was floated to use students' fingerprints to access payment of their school lunches.
This would put another spin on the information we don't keep around the library about our patrons. I imagine that the FBI would love to be able to pull fingerprints along with usage records during a Patriot Act visit.