In 2015, Chinese agents hacked the U.S. Office of Personnel Management and stole security clearance files of more than 21 million employees

In 2015, Chinese agents infiltrated the U.S. Office of Personnel Management and stole security clearance background check files of more than 21 million current and former federal employees, including fingerprints, financial records, foreign contacts, psychological evaluations, marital issues, medical records and other sensitive background investigation materials.