Details of the NSA's ability to record and review phone calls in foreign countries liken the agency's technology to a time machine.

The Washington Post reports documents supplied by former contractor Edward Snowden reveal an NSA surveillance system capable of recording 100 percent of a country's phone calls.

That same system has the ability to rewind and review calls for up to 30 days.

At the request of the U.S. government, the paper is not revealing in which country the bulk collection of data is occurring.

However, it's reporting that high volume eavesdropping may soon be increasing.