"Please cover your crown jewels," asks the group's listing, which had initially only called for current or former service members for submissions.
Last Wednesday, TMZ published two photos of Prince Harry playing "strip billiards" on his Las Vegas vacation, scandalizing the royal family but eliciting millions of delighted squeals around the world.
Most of the photos use strategically placed flags, army berets or even guns to express their appreciation for Harry, 27, who could face a serious dressing-down from his superiors in the British military.
"This is for fun, friendly harmless fun to support Prince Harry," the group administrator warns on the site. "Please respect the rules, keep it clean, cover your crown jewels and royal assets and show us your best salute, thank you for your continued support - We salute you Prince Harry ;)"
Facebook users aren't the only Harry fans to defend the prince, whose exploits have long been fodder for the tabloids. Media mogul Rupert Murdoch stuck up for Harry's right to go wild in Vegas on Twitter Saturday.