The United States is losing enough data in cyber attacks to fill the Library of Congress many times over, and authorities have failed to stay ahead of the threat, a U.S. defense official said on Wednesday, Reuters reports. More than 100 foreign spy agencies were working to gain access to U.S. computer systems, as were criminal organizations, said James Miller, principal deputy under secretary of defense for policy. Terrorist groups also had cyber attack capabilities. “Our systems are probed thousands of times a day and scanned millions of times a day,” Miller told a forum sponsored by Ogilvy Washington, a public relations company. He said the evolving cyber threat had “outpaced our ability to defend against it.” “We are experiencing damaging penetrations — damaging in the sense of loss of information. And we don’t fully understand our vulnerabilities,” Miller said.