The US Navy has issued new rules forbidding personnel from sharing intimate photographs without consent.
They ban the sharing of images when "the person depicted had a reasonable expectation of privacy" or "without legal justification or excuse".
It follows the discovery that some marines were sharing photos of women in a private Facebook group.
Service personnel found to be violating the regulations will be dealt with by military courts.
The interim order, which was signed on Tuesday, is expected to be made permanent in the next edition of the US Navy regulations.
Taken without consent
The photos began to appear on the members-only Marines United group in January, when the first US Marine infantry unit began admitting women.
They were often accompanied by obscene comments and some of the women in the pictures were identified by name, rank and unit.
Membership of the group, now closed, was limited to active and retired male US Marines and Navy Corpsmen, and British Royal Marines.
A spokesperson for the Royal Navy said that as the images were posted by US Marines, it was "a matter for the US authorities".
Some of the images appeared to have been taken covertly, while others are believed to have been taken with the women's consent but posted without permission.
Facebook and Google closed the social media accounts of those posting the images, following a request from the US Marine Corps.
A Google Drive folder hosting the images was also deleted.