Obama signed the new transportation bill into law, along with the provisions of it that require the IRS to farm out some of its unworked inventory of tax arrears to private debt collection companies and that allow for the revocation or denial of passports to people with more than $50,000 in unpaid taxes.
Tax authority Kelly Phillips Erb has a good write-up on the ramifications of that second provision. And you can read the text of the law as-signed if so inclined.