There are currently 11 sanctuary states in the US. Sanctuary policies are those followed by towns, cities, counties, states, and other jurisdictions that restrict most forms of cooperation with federal immigration authorities. While jurisdictions are not compelled by federal law to participate in federal immigration enforcement activities, federal law prohibits them from actively obstructing enforcement of federal law. In addition, sanctuary policies may violate the supremacy clause of the United States Constitution and the 10th Amendment. Sanctuary policies may place the public at risk by preventing the federal authorities from locating, arresting, and prosecuting criminal aliens. Currently, there are 11 states that have through executive action or passage of a law declared themselves “sanctuary states.” Although not a state, the District of Columbia is also considered a sanctuary jurisdiction. All are part the approximately 600 sanctuary jurisdictions in the U.S., most of which were established after 2000.