Legal Deposit Libraries Act

["Joseph J. Esposito" <espositoj@gmail.com>]

There is an opinion piece in the Guardian by Nigel Newton, head 
of Bloomsbury Publishing, in which Newton excoriates Google for 
the Google Print for Libraries project.  While Newton says 
nothing that would be news to members of this list, he makes a 
reference to the Legal Deposit Libraries Act that is unfamiliar 
to me:

"And because they [participating libraries] are copyright 
libraries, publishers are obliged by the Legal Deposit Libraries 
Act to give one copy of each book to those six copyright 
libraries for free. No one ever said it could be passed on in 
electronic form to a third party."

Can anyone shed light on this?  Is the Act a UK thing, American, 
something besides (Ruritanian?)? The URL is 
http://books.guardian.co.uk/comment/story/0,,1722888,00.html, and 
the piece is entitled "Google's Literary Land-grab."

Joe Esposito