The US Department of Defense was afforded a surprise during a hearing on 10 April 2013 of the House Armed Service Committee when Representative Doug Lamborn began quoting from an “unclassified” Defense Intelligence Agency report on the nuclear capabilities of North Korea. The DIA apparently neglected to place appropriate classifications on the North Korea assessment (Lamborn/Dempsey exchange). This inadvertent disclosure put in the hands of a potential adversary (North Korea) The ramifications? Could it happen to entities which fall under the National Industrial Security Programs of the DOD? Absolutely, the annual training requirement contained in NISPOM section 3.”]
Source: https://www.csoonline.com/article/2133432/inadvertent-disclosure–knowing-the-risk.html