I've never had the overprotective problem, but some of my guy friends have hung around to give the warning glare to any creepy guys who approach me. I really don't mind since they aren't over zealous about it and it feels like I have my own personal security when a creep does come around. One of them told me a mutual friend of ours had a VERY creepy con stalker before I knew them so he (understandably) likes to look out for his female friends at cons. I also knew a dad who was fine with his daughter cosplaying revealing outfits as long as he went to the con with her to make sure nobody tried anything.
"No one has ever written or painted, sculpted, modeled, built, invented, except to get out of hell." -Antonin Artaud