The U.S. Border Patrol is monitoring millions of American drivers nationwide in a secretive program to identify and detain people whose travel patterns it deems suspicious, The Associated Press has found.

After nearly a week in Charlotte, Border Patrol is planning to end Operation Charlotte's Web soon, according to an NBC News report. Two United States Department of Homeland Security officials told NBC News that the operation would be ending soon, "at least for now," and that Border Patrol may later return to the Queen City to resume its work.