Main Core

I came across this article on Wikipedia that discloses the existence of a FEMA run government program that purports to contain a list of "persons of interest" to the United States government in the event of a crisis.

Main Core is the code name of a database maintained since the 1980s by the federal government of the United States, which contains personal and financial data of millions of U.S. citizens believed to be threats to national security. The data, which come from the NSA, FBI, CIA, and other sources, are collected and stored without warrants or court orders. The database's name derives from the fact that it contains "copies of the 'main core' or essence of each item of intelligence information on Americans produced by the FBI and the other agencies of the U.S. intelligence community."

The Main Core database is believed to have originated with the Federal Emergency Management Agency (FEMA) in 1982, following Ronald Reagan's Continuity of Operations plan outlined in the National Security Directive (NSD) 69 / National Security Decision Directive (NSDD) 55, entitled "Enduring National Leadership," implemented on September 14, 1982.
As of 2008 there are reportedly eight million Americans listed in the database as possible threats, often for trivial reasons, whom the government may choose to track, question, or detain in a time of crisis.
The existence of the database was first reported on in May 2008 by Christopher Ketcham and in July 2008 by Tim Shorrock.

Source: Wikipedia