In March, it was revealed US Marines had shared nude photos of female colleagues in a closed Facebook group – later the scandal expanded to include the entire Pentagon. While Department of Defense response was swift and robust, it has been revealed service members had complained about the issue months before the indignity was publicly revealed.

In a report, the Pentagon admitted around 6,200 members of the US military had experienced sexually explicit photos of them being taken or shared against their will by colleagues, which made them feel "uncomfortable, angry or upset." The finding is drawn from an internal survey on individual experiences of the military, which was dispatched to 735,000 service members between June and October 2016, and generated 150,000 responses.

Need to talk? Someone is always available at SafeHelpline. https://t.co/lsyl34EQvh — U.S. Army SHARP (@USArmySHARP) April 23, 2017

​Over For Department of Defense community members affected by sexual assault — anonymous, secure, available 24/7. Thank you @USArmySHARP! #SAAM https://t.co/leIEdWpUI4

​22,000 service members also reported being upset or angry when someone at work showed or sent them pornography, with female Marines again representing the highest percentage of complaints from women.

The revelations came to military attention long before the nude photo scandal came to light, but were hitherto obscured from public view. Then, it was revealed that alongside taking intimate photos of female soldiers without permission, posters to the private Facebook page – which boasted 30,000 members – also reposted innocent photos stolen from female Marines' social media accounts, and discussed their looks – many lewd and/or offensive comments were made, and rape was often discussed.

The existence of the photos was revealed by the Center for Investigative Reporting, who worked with veteran Thomas Brennan, founder of The War Horse, a non-profit military and veterans-journalism organization. Brennan and his family went on to receive death threats, with a bounty of US$500 being offered for nude photos of Brennan's wife.

The revelation triggered a criminal investigation that expanded to encompass the entire US military, and produced a variety of punishments for offending service people, and changes to internal social media policies.

The survey was released as part of the Pentagon's annual report on sexual assault and harassment in the military. It found reports of sexual assaults in the military increased slightly in 2016, and over 50 percent of victims reported receiving negative reactions or retaliation for their complaints.

Swapping nude photos is now a crime in the Navy and Marine Corps: https://t.co/U8lWo80KbK pic.twitter.com/8nlqQj0osP — Navy Times (@NavyTimes) April 19, 2017​

Spokespeople were quick to note the survey showed some progress in battling the issue of sexual assault in the military, as fewer than 15,000 service service people – 4,000 fewer than in 2014 – were the victim of unwanted sexual contact.

Questions related to social media harassment were asked for the first time in 2016's survey, as the issue has become more of a concern in recent years. According to the data, 1.3 percent of military women said someone took or shared explicit photos of them against their will. When divided according to military service, 2.3 percent of female Marines made that complaint, compared to 1.5 percent of female soldiers, 1.6 percent of female sailors and 0.5 percent of female aviators.

The Marine Corps is the smallest military service, so while the percentages were the largest, the actual numbers of people affected are perhaps smaller than other services. Separately, data released by the Pentagon on Monday (May 1) showed there were 6,172 reports of sexual assault filed in 2016, compared to 6,083 the previous year. The largest increase occurred in the Navy, with 5 percent more reports. There was a 3 percent jump in the Air Force. The Army and Marine Corps had slight decreases.

In respect of official responses, 58 percent of victims said they faced some type of "negative behavior" after reporting such incidents, although only 32 percent described circumstances that could legally be described as retribution. This includes professional retaliation, administrative actions or punishments. In 2015, this figure was 38 percent. Of the 14,900 who experienced some type of unwanted sexual contact, 8,600 were women and 6,300 were men.

Other reports suggest victims are frequently subject to further abuse, one in seven victims are assaulted or harassed by someone in their chain of command, and a third of victims are discharged within seven months of reporting abuse. Victims also receive harsher discharges, with 24 percent discharged under less than fully honorable conditions, compared to 15 percent of all service members.

Sexual abuse scandals have blighted many other militaries. In February, an investigation found female soldiers were systematically forced to perform humiliating strip and pole dancing shows for officers at a German military base, as part of their "initiation."