According to a senior government official who served with high-level security clearances in five administrations, "There exists a database of Americans, who, often for the slightest and most trivial reason, are considered unfriendly, and who, in a time of panic, might be incarcerated. The database can identify and locate perceived 'enemies of the state' almost instantaneously." He and other sources tell Radar that the database is sometimes referred to by the code name Main Core. One knowledgeable source claims that 8 million Americans are now listed in Main Core as potentially suspect. In the event of a national emergency, these people could be subject to everything from heightened surveillance and tracking to direct questioning and possibly even detention.
[H/T 2 Survivalist News via Bear Ridge Project.]