I don’t like to get into controversial topics, but this is what I’ll say. There’s a certain why to conduct yourself on the streets whether you’re a frum girl a frum boy, or a secular boy or girl. Chewing gum loudly or while talking is rude and can look disgusting, but that has nothing to do with being a frum girl. It’s called being a person. In my opinion, this is not a tznius issue. It’s manners. And I don’t think it’s appropriate to stereotype “modern” girls. Like Imaofthree said, we have bigger things to worry about.
MiddlePath, I agree that we shouldn’t judge people based on how they dress. I’m guilty of doing this, too.
I also think girls (and guys) need to have some fun instead of constantly looking over their shoulder to make sure no one is “studying” them.
yossi2468, you better be joking or I’ll crawl through my screen and slap you across the face 😉