Theft and looting, as covered by this website, tends to focus on illegal excavations & looting of archaeological sites, some of which isn’t discovered until well after the event. One must remember though, that huge amounts of art theft also take place directly from museums and private collections – and that many of these cases remain unsolved.
Washington Post 
Three books on art theft
By Christopher Schoppa, Published: October 7
The craft of looting precious artworks is almost as old as the medium itself, with countless cases littering the pages of history, from casualties of war (most recently, the Baghdad Museum) to brazen museum heists (Boston’s Isabella Stewart Gardner Museum in 1990). There are also the thorny issues of national patrimony, art that by chance or pillage wound up as the backbone of some other country’s elite museum: The famed Elgin Marbles now housed in the British Museum are a prime example. Greece has a state-of the art (yet empty) space to house them in the Acropolis Museum, and is still waiting. But you needn’t. For more tidbits on all manner of displaced works of art, read on.
1. Stealing Rembrandts: The Untold Story of Notorious Art Heists, by Anthony M. Amore and Tom Mashberg (Palgrave Macmillan, $25). As the title suggests, the authors focus on the 17th-century Dutch artist Rembrandt Van Rijin and the vast body of work he left behind, With conservative estimates placing authentic Rembrandts at over 1,000, thieves have an ample selection from which to choose. Amore is the director of security at the Gardner Museum in Boston, which lost three Rembrandts among the 13 masterpieces swiped in the dead of night. Becoming obsessed with the case (still unsolved), Amore used his investigations as a jumping off point to explore the appeal of Rembrandt’s works for thieves and the entry of organized crime into art theft. He was aided by former Boston Herald reporter Mashberg, who wrote about the case on and off for 14 years (even being whisked off to an undisclosed site purportedly to see one of the stolen Rembrandts). Together they tell a compelling story.
2. Art Theft and the Case of the Stolen Turners, by Sandy Nairne (Reaktion, $29). The author is director of the National Portrait Gallery in London, but his book focuses on his tenure at the Tate Gallery as director of programs. In 1994, two of the Tate’s renowned paintings by J.M.W. Turner were stolen while on loan to a gallery in Frankfurt. Nairne’s insider’s chronicle of the investigation and subsequent recovery of the paintings via negotiation often reads like a fine arts version of “The Thomas Crown Affair.” And that romanticized perception — a crime of derring-do by suave gentlemen or plucky outsiders — is part of the problem. When committed by real criminals, he points out, the theft of art is often linked to drugs, prostitution or money laundering. Nairne also details the herculean efforts being undertaken by Interpol and institutions worldwide to safeguard art.
3. The Shakespeare Thefts: In Search of the First Folios, by Eric Rasmussen (Palgrave Macmillan, $24). True bibliophiles know that rare books can be as precious as many canvasses hanging in prestigious museums. This gripping narrative finds Rasmussen, a noted Shakespeare scholar, tracking down every copy of what is arguably the most sought-after book on Earth — William Shakespeare’s First Folio, published in 1623. Only 232 copies survive, and Rasmussen circles the globe to find them in public and private collections and to speculate on the whereabouts of those that are missing or known to have been stolen. With him on the journey is a team of assistants called the First Folio hunters, whose presence lends the book a reality-TV tinge. Actually, it’s not a bad premise for a television series.