National Security Agency Director Gen. Keith Alexander on Wednesday denied a report that the agency had tapped communication links between Yahoo and Google data centers around the world, saying any information the U.S government obtained from the service providers came through a court order.

The Washington Post reported Wednesday that the NSA had secretly broken into Yahoo and Google databases. The paper cited documents obtained by former NSA contractor Edward Snowden and interviews with knowledgeable officials.

By accessing Google and Yahoo data centers, the story said the NSA positioned itself to collect at will information from hundreds of millions of user accounts, many of them belonging to Americans.

Alexander, who was speaking at a previously scheduled cyber-security event hosted by Bloomberg News, said he had not read the Post report, but insisted the NSA is “not authorized” to access companies' data centers and must “go through a court process” to obtain access to Google and Yahoo’s data.

Once the NSA obtained a court order from the Foreign Intelligence Surveillance Court, said Alexander, service providers are “compelled” under U.S. law to provide the requested data.

Critics of the NSA's bulk surveillance programs have said those court orders are too easy to obtain, but Alexander said it's easier for law enforcement agencies to obtain information on common criminals than it is for intelligence agencies to seek permission to access private company data.

“We're making this harder to go after terrorist information than we do our own criminals,” he said, “But that's how we set up this framework to ensure we are doing everything right.”

Alexander acknowledged that the agency accesses privately-held data, but said those data culls were narrower in scope, limited to thousands not millions of users. He added that the surveillance of service provider information has “nothing to do with U.S. persons.”

During the question and answer session, the general was asked whether NSA tapped data centers surreptitiously.

“Not to my knowledge,” Alexander said.

Google and Yahoo both told the Post they did not grant the NSA access to their data centers.