“Data available through ICREACH appears to be primarily derived from surveillance of foreigners’ communications, and planning documents show that it draws on a variety of different sources of data maintained by the NSA. Though one 2010 internal paper clearly calls it “the ICREACH database,” a U.S. official familiar with the system disputed that, telling The Intercept that while “it enables the sharing of certain foreign intelligence metadata,” ICREACH is “not a repository [and] does not store events or records.” Instead, it appears to provide analysts with the ability to perform a one-stop search of information from a wide variety of separate databases. In a statement to The Intercept, the Office of the Director of National Intelligence confirmed that the system shares data that is swept up by programs authorized under Executive Order 12333, a controversial Reagan-era presidential directive that underpins several NSA bulk surveillance operations that monitor communications overseas. The 12333 surveillance takes place with no court oversight and has received minimal Congressional scrutiny because it is targeted at foreign, not domestic, communication networks. But the broad scale of 12333 surveillance means that some Americans’ communications get caught in the dragnet as they transit international cables or satellites—and documents contained in the Snowden archive indicate that ICREACH taps into some of that data. Legal experts told The Intercept they were shocked to learn about the scale of the ICREACH system and are concerned that law enforcement authorities might use it for domestic investigations that are not related to terrorism.

“To me, this is extremely troublesome,” said Elizabeth Goitein, co-director of the Liberty and National Security Program at the New York University School of Law’s Brennan Center for Justice. “The myth that metadata is just a bunch of numbers and is not as revealing as actual communications content was exploded long ago—this is a trove of incredibly sensitive information.” Brian Owsley, a federal magistrate judge between 2005 and 2013, said he was alarmed that traditional law enforcement agencies such as the FBI and the DEA were among those with access to the NSA’s surveillance troves. “This is not something that I think the government should be doing,” said Owsley, an assistant professor of law at Indiana Tech Law School. “Perhaps if information is useful in a specific case, they can get judicial authority to provide it to another agency. But there shouldn’t be this buddy-buddy system back-and-forth.”