Many Berliners believe that tampering with the wall, which is protected as a historical monument, shows how the city's identity is shifting amid development and commercialization.

WSJ: In Berlin, Wall Divides Developers, Protesters

"I wish to emphasize that, as a Berlin-based company, we are just as interested in the preservation of the East Side Gallery as a historical monument as are Berliners and people in the entire world, " he said.

WSJ: In Berlin, Wall Divides Developers, Protesters

Last November, I was proud to establish the Fort Monroe National Monument, forever enshrining a site of profound historical and cultural significance.

WHITEHOUSE: Presidential Proclamation -- National Park Week, 2012