19th century imperial adventurers did rather think they could help themselves to anything they came across on their travels. Captain Richard Powell, for instance, who fetched up on Rapa-Nui (Easter Island) in 1868, thought he'd like to take one of the Moai home with him as a souvenir. So he did- and gave it to Queen Victoria who gave it to the British Museum. The people of Rapa-Nui would now like their statue back. To us Brits it's just an imposing bit of basalt, to them it's a part of who they are- not just an image of an ancestor but an embodiment of the ancestor. The rights and wrongs are clear. It's stolen goods. It should go back.