http://www.dailyrotten.com/source-docs/patriot2draft.html The limitation to international terrorism in existing law is an impediment to the effective use of national security letters because it may not be apparent in the early stages of a terrorism investigation-or even after it has continued for some time-whether domestic or international terrorism is involved. The Oklahoma City bombing and the anthrax letter incidents illustrate this point. Moreover, in the current circumstances, domestic terrorists who attempt to ally with or are inspired to emulate international terrorists are an increasing concern. The dangers posed to the national security by such persons may be comparable to those posed by international terrorists, and national security letters should likewise be an available tool in the investigation of their criminal activities.