A high school in London will use a retina scanning device to charge students for lunch. The scanner will also be used in the library.
Coverage is here.
The program simply aims to eliminate the embarrassment caused to poor students, who eat lunch for free--a cause which I fully support.
Put in far less compassionate terms, though, in this instance the cost of avoiding social stigma for some is a compromise of privacy for all. Given the trade offs, I think magnetic strips on ID cards would have been a better alternative.