Tween commandos clique harmless phase or something deeper?

What would you make of a group of tween girls that call themselves The Commando Cuties whos unofficial uniform is a mini and lime green spaghetti tops with matching scrunchies. Once they leave home to go to the ball game, mall, library, etc, they rush to the ladies’ room and deftly remove their panties and bras but make sure to put them back on before going home. Would you think it was a harmless phase or something that need to be addressed?