The Brent decision hinged on the 1964 Public Libraries and Museums Act, which says local authorities must provide a "comprehensive and efficient library service", and may determine how far other local authorities can go with their planned closures.

BBC: Library cuts: The battle of the bookshelves

It's a balancing act that presidential libraries have addressed to sometimes jarring effect.

WSJ: Bricks and Immortality | George W. Bush Presidential Center | By Julie V. Iovine

She pointed out that the Children's Internet Protection Act already requires libraries to block net content that is harmful to children.

BBC: Many schools have already banned social network sites