Securing the Washington Monument from terrorism has turned out to be a surprisingly difficult job. The concrete fence around the building protects it from attacking vehicles, but there’s no visually appealing way to house the airport-level security mechanisms the National Park Service has decided are a must for visitors. It is considering several options, but I think we should close the monument entirely. Let it stand, empty and inaccessible, as a monument to our fears.
Bruce Schneier absolutely nails it in Close the Washington Monument.