The last major point is that if the Greeks would have protested the removal of the marbles at the time it was occurring, they would have been brutally beaten and imprisoned by the Turks.
The website that best represents the side of the United Kingdom is http://www.guardian.co.uk/elgin/article/0,2763,645128,00.html, this website claims that forcing museums and libraries to give back artifacts to the country they originated from cause many great centers of education to lose their great collections. The author's main point is simply that great artifacts like these need to be shared with the world. The marbles are reaching more eyes and educating more people in their home in the London Museum than they would if they were removed back to Greece, besides most people in Greece learned about the marbles through history classes in their country's education system, most people who see them in the London museum hadn't been very educated about them. The London museum simply attracts more of an international audience and spreads the knowledge of the marbles more than Greece's New Acropolis museum ever could. Do we believe that the Smithsonian Institute in Washington D.C. should only hold artifacts from the American culture, of course not, museums and libraries should not be confined to only house artifacts and works from their respected culture. This website offers quite a few links to other sites with more information on the matter and also offers links to sites with the opposite point of view.
In my opinion, the marbles should be returned to Greece simply because they were bribed from the Turkish conquerors and had no right to be removed. They are a very important part of Greece's ancient history and they should have ownership. It would be ridiculous if some country came to America and took the Statue of Liberty to put in their museum. Not that great museums and art galleries of the world should be deprived of their prized foreign collections but they should at least be obtained in a moral way.