The U.S. State Department will begin revoking the U.S. passports of thousands of parents who owe a significant amount of unpaid child support. The department told The Associated Press on Thursday that the revocations would begin Friday and be focused on those who owe $100,000 or more. That would apply to about 2,700 American passport holders, according to figures supplied to the State Department by the Department of Health and Human Services . The revocation program, plans for which were first reported by the AP in February, soon will be greatly expanded to cover parents who owe more than $2,500 in unpaid child support — the threshold set by a little-enforced 1996 law, the State Department said. It was not clear on Thursday how many passport holders owe more than $2,500 because HHS is still collecting data from state agencies that track the figures, but it could encompass many more thousands of people, officials said.…