18 U.S. Code § 793 - Gathering, transmitting or losing defense information

(f) Whoever, being entrusted with or having lawful possession or control of any document, writing, code book, signal book, sketch, photograph, photographic negative, blueprint, plan, map, model, instrument, appliance, note, or information, relating to the national defense, (1) through gross negligence permits the same to be removed from its proper place of custody or delivered to anyone in violation of his trust, or to be lost, stolen, abstracted, or destroyed, or (2) having knowledge that the same has been illegally removed from its proper place of custody or delivered to anyone in violation of its trust, or lost, or stolen, abstracted, or destroyed, and fails to make prompt report of such loss, theft, abstraction, or destruction to his superior officer—
Shall be fined under this title or imprisoned not more than ten years, or both.


[link to www.law.cornell.edu (secure)]

Gross negligence

A lack of care that demonstrates reckless disregard for the safety or lives of others, which is so great it appears to be a conscious violation of other people's rights to safety. It is more than simple inadvertence, and can affect the amount of damages.

[link to www.law.cornell.edu (secure)]

Gross negligence is a conscious and voluntary disregard of the need to use reasonable care, which is likely to cause foreseeable grave injury or harm to persons, property, or both.

[link to legal-dictionary.thefreedictionary.com]

Extreme Carelessness = Gross negligence.