It has emerged that us servicemen from all parts of the military have been sharing nude photos of their female colleagues online.
Reports last week uncovered widespread photo sharing by current and former marines on Facebook, triggering a navy investigation.
The pentagon said such behaviour was inconsistent with its values.
Male service members use a message board on anonymous image hosting website Anon-Ib to share nude images of their female counterparts.
They often first post clothed photos of female personnel taken from their social media pages, and ask if any members have nude photos, which they call wins.