U.S. officials tell the Associated Press that the government's phone monitoring program was responsible for cracking a 2009 plot to bomb the city's subway system.
Najibullah Zazi pleaded guilty in connection with that plot.
He's in prison, serving a life sentence.
A U.S. intelligence official told the AP that investigators were able to stop him in part because of phone records collected by the National Security Agency.
President Barack Obama defended his administration Friday as controversy swirled over the reports that the federal government gained wide access to both private phone records and internet data.
Obama said that the programs, some of which started during the Bush administration after the September 11th attacks, are a necessary defense against terrorism.
He said no one is listening to the content of phone calls, and only foreigners with suspected ties to terrorism are being targeted in internet investigations.
"You can't have 100 percent security and also then have 100 percent privacy and zero inconvenience," he said. "We're going to have to make some choices as a society."
According to the Washington Post and The Guardian, the National Security Agency and the Federal Bureau of Investigation have been tapping into the servers of nine companies under a program called PRISM.
The companies include Microsoft, Apple, Google and Facebook.
A classified document reportedly shows that the NSA and FBI obtained video and audio chats, pictures and emails in an effort to follow targets overseas.
The report comes a day after a report revealed the government ordered Verizon to hand over information on all telephone calls in its system on a daily basis.
The White House said officials only use the records to obtain information like how long a call lasts and which numbers are dialed.