Senator Rand Paul has won. The Republican running for president was able to block action on the Patriot Act, so three key provisions expired at midnight.
FOX News Radio's Jon Decker in Washington, D.C. has more:
After Kentucky Senator Rand Paul delayed a vote on the Patriot Act, the NSA's ability to collect the phone records of millions of Americans in bulk expired at midnight.
The expiration of the Patriot Act also means that, for now, the F.B.I. cannot obtain wiretap orders that follow a suspect who changes phones or wiretap orders for a so-called "lone wolf" terrorism suspect.
The NSA program is likely to be revived in some form in the coming days, after Senate Majority Leader Mitch McConnell reluctantly embraced a House-passed bill, known as the USA Freedom Act.
In Washington, Jon Decker, FOX News Radio.