Matt Warman talks exclusively to Facebook's engineering chief about life at the world's biggest social network.

All the modern greats are exhibited here: Matisse, Mondrian, Warhol, Kandinsky, Picasso, Bacon, Cezanne, Monet, Dali, Duchamp, man Ray, Rodin, the Chapman brothers and many many more.

In his paper, Pooley examines coverage of last June's Senate debate over the Warner-Lieberman Climate Security Act, the first carbon cap-and-trade bill to get a real hearing in Congress.