The Library of Congress email systems suffered a substantial hack earlier this year by a "foreign adversary," Fox News can confirm.It is unclear if the hack compromised accounts of those who work directly for the House and Senate.However, Fox News is told that U.S. Capitol Police has referred the matter to the FBI, and it is investigating the scope of the hack.The hack was described to Fox News as "classic, sophisticated foreign adversary espionage."CHINESE SPIES HACKED TRUMP ATTORNEY TODD BLANCHE'S PHONE: SOURCEThis means that the foreign actor conducting the hack was likely trying to get a sense of what types