http://news.bbc.co.uk/2/hi/world/europe/10136767.stm

“Officials have admitted the Museum of Modern Art’s alarm system had not been fully functioning for several weeks.

One masked intruder was spotted by security cameras, climbing into the museum through a broken side window, having cut through a gate padlock.

The paintings are estimated to be worth just under 100m euros (£86m; $123m).

But experts say the thieves would struggle to sell the paintings on the open market because they are so well known.

The five missing paintings are Dove with Green Peas by Pablo Picasso (painted in 1911), Pastoral by Henri Matisse (1906), Olive Tree near l’Estaque by Georges Braque (1906), Woman with Fan by Amedeo Modigliani (1919) and Still Life with Candlestick by Fernand Leger (1922).”

The link also provides a great history of art heists.