A female Marine finds photos from her personal Facebook account re-posted on a Marine humor page and subjected to derogatory and sexual comments. This happens not once, but again and again, and it doesn’t stay online:  she gets honked and yelled at in the street when she’s walking near her base, and her friends tell her she’s developed a reputation as a “barracks mattress,” because Marines think that if she gets posted to these sites,  she must be a slut. On Facebook pages like “Just The Tip, Of The Spear,” and others, most users say there’s no problem with what…