I guess that maybe they were concerned "The Spirit of St. Louis" or maybe the German Fokker D.VII would be refurbished and flown over Afghanistan.

Reuters:

Authorities shut down Washington's popular National Air and Space Museum on Saturday afternoon after antiwar protesters tried to enter the building and clashed with guards, a museum spokeswoman said.

One person was arrested during the melee at the Smithsonian museum involving between 150 and 200 protesters and six guards, museum spokeswoman Isabel Lara said.

"There was a lot of shoving going on," Lara said, adding one of the guards was surrounded and used pepper spray before the demonstrators were moved outside. She said she was not aware of any injuries.

The shoving match broke out in a vestibule between two glass doors at the museum entrance after guards told the protesters they could not enter with signs, Lara said.

Protest organizers said the attempt to enter the museum on the National Mall was part of the Occupy D.C. antiwar demonstrations that began on Thursday on the 10th anniversary of the start of the Afghanistan war.

I don't get it. Oh, wait...

"Along with the Occupy Wall Street movement, it represents an upswell of people taking to the street around the country to demand social and economic justice as well as an end to the immoral wars in Iraq and Afghanistan," organizers said in an e-mail sent to Reuters.

"It is outrageous that the security guard of a major museum in America pepper sprayed Americans as they entered the museum. The drones housed in this museum and the pepper spraying of Americans at the door are clear evidence of repression in America," Retired Colonel Ann Wright said in the e-mail.

Or it's clear evidence that you shouldn't go pushing and shoving those whose job is to safeguard historic treasures that are on display at the museum. At least a bull in a china shop is too dumb to respect the property of others and the aesthetic and historic value of certain items.

What's the excuse of the CodePink loonies?