Throughout history, there have been many cases where items of cultural property have been taken from their original owners & often put on public display. In recent years though, public opinion on this type of practice has changed, with more laws & regulations to try & prevent this from happening.
Salt Lake Tribune 
Ancient artifacts slowly gaining protection – and it’s about time
By Pat Bagley
The Salt Lake Tribune
Updated: 06/27/2009 04:53:22 PM MDT
In 1802, Lord Elgin began stripping a good chunk of Greece’s cultural heritage to decorate his Scottish estate.
Two hundred years ago, the Ottoman Empire embraced the Middle East and southeastern Europe, including Greece. As British ambassador to the Sublime Porte (the Ottoman seat of the Sultan in Istanbul), Elgin admired the ancient statuary and friezes that adorned the Acropolis in Athens. He liked them so much he prevailed on the Turks to let him have them (the proper palms being greased along the way, of course).
Some of the bigger pieces couldn’t be hauled away, and so were sawn apart to facilitate shipping. In all, about half of the Acropolis decoration and statuary ended up in the British Museum.
All perfectly legal.
When the Greeks won their independence, they wanted their stuff back. The British to this day have declined, arguing they came by them fair and square and have the paperwork to prove it.
As a child visiting from California, I thought my Utah cousins were exotic. Besides snow and speaking with an accent, they also dug up buried treasure. Mostly this consisted of broken bottles retrieved from pioneer midden pits (before trash pick-up, every home used to have its own trash dump out back).
I also remember the Indian artifacts. There were the potsherds and arrowheads and dried ears of corn. But even as a 6-year-old, there were some things that I recognized as extraordinary. And slightly creepy. Something about burial mounds.
On those trips to Utah in the early 1960s, the family would visit the pioneer museum on Temple Square. The building has since been torn down, the site currently occupied by the gleaming visitor’s center in the southeast corner.
I remember two things from the old museum. One was a clever device, carved out of wood, that counted the rotations of a wagon wheel. (Orson Pratt’s early odometer turned out to be pretty accurate.)
The other was an Indian mummy in a glass case.
Of the two, the mummy won, hands down. I remember elbowing other sweaty kids out of the way to get a good look.
I didn’t register any moral queasiness at the time. Cultural norms were different back then — unless your culture happened to be native American and that fella under glass was great-grandpa, no one seemed to think anything of it.
Over time, we have rethought things. You could say we’ve become empathetic.
You don’t need to put Brigham Young on display in the Smithsonian’s Native American museum in Washington, D.C., to realize that one ought to be sensitive to other people’s stuff.
In time the LDS Church turned over the Indian remains, my cousins wouldn’t dream of poaching items on federal land, and I’ll return that fingernail-sized piece of pottery that I picked up in Southern Utah the next chance I get.
Now if only the British would get the message.