There was an interesting article in today's NYT online regarding the recovery of stolen artwork in Madrid. Some works by Goya, Gris and Pisarro were stolen from a Madrid home and recovered through the joint efforts of the Spanish police and the FBI.

The website is: http://www.nytimes.com/2002/06/26/arts/design/26THEF.html
(you need a password, but it is free to login).