The largest group of foreign nationals falls under the authority of the Secret Service or the State Department. In order to encourage Federal cooperation with local law enforcement counterparts, the Secret Service established the Dignitary Protection School in Washington, D.C. In general, the protection of foreign nationals in the United States is probably harder than in any other country of the world. Foreign nationals enter the United States by every conceivable means, and most foreigners are familiar with the process of contacting the American embassy in a foreign country to apply for a visa to the United States. With cultural and language barriers, foreign nationals impose hardships on the police's ability to provide basic protection. Further, foreign nationals often quickly adapt to the freedoms of many Americans and aggressively exercise these freedoms in demonstrations and interaction with the police. In exercising their freedoms, foreign nationals frequently exceed legal limits and violate other persons' rights. Serious attention should be given to responding proactively to crimes committed by foreign nationals, especially with regard to terrorist incidents and threats.