There is a big difference between making a generalization about someone based solely on attire (or their job), and assessing someone's character based upon their behavior and conduct. If someone wants respect from others they must first respect themselves, and if someone treats and presents their own body like an object, naturally others will perceive it as such. And when people decide to be sexually provocative for the sake of attention, they should except that not all of the attention will be favorable. Actions tend to get reactions of similar class and caliber.
No girl deserves to be mistreated and degraded, but obviously behavior that's considered irresponsible and risky will increase the changes of being exposed to that sort of thing. When people make choices, they should accept the potential consequences that come with them. Again, that doesn't excuse or justify the words and actions of misogynists, so don't try to stretch or twist what I'm saying to make be out to be an apologist for them. Let's say, for example, I wandered into an inner-city, crime ridden ghetto flailing around clearly visible bags of money in my hands, and then was robbed and murdered because of it. They would still be in the wrong for robbing and killing me even though my actions would be considered extremely foolish. It's not either/or.
Obviously what some of these guys are saying is wholly ignorant and completely inappropriate, but as long as they aren't harassing, stalking, assaulting, or violating anyone's rights in any other way, then it falls under free speech. Therefore the best way to combat such language is to simply not visit the site.
Illegally obtaining photos, however, is a serious violation of privacy.
The thing is, I don't think it's "illegal" to raid women's facebook pages for pictures of them goofing around with their friends, taken by their friends, in what they probably assumed was a generally friendly and open environment, in a sexually provocative way. The fact that Facebook hasn't taken down any of the photos that were reported except one or two shows they're totally OK with that.
Sure, I could say that they could have protected their photos from being harvested by misogynists by establishing better privacy settings on facebook, and maybe they're kind of silly for not doing that, but I don't think it's reasonable to say we (women) should all just assume we're inevitably going to be called sluts and hoes, smelly and dirty, disease infested, walking dick holes, yada yada if we share a photo of us with our top off, or in a skimpy summer outfit, or whatever.
The whole point of sexual liberation is to gain the freedom for women to be openly sexually expressive beings without being attacked, disparaged or harassed. You have to admit, that's a good deal for everybody. Women who want to wear a bikini top to a summer festival AND men who want to see women in bikini tops.
Knuckle-dragging, backward idiots like the fans of Festival Sluts kind of ruin it for everybody. The more women have to worry about being harassed for showing some skin, the less skin there will be for heterosexual men to look at in public.
I'm not prepared to say "that's just how it is, suck it up". If that's how it is, we might as well all move to Afghanistan and wear a bag over our heads, since the arguments for that kind of attire are the same as your arguments above: Men are pigs and can't look at a scantily-dressed woman without verbally or physically assaulting her.
The situation is constantly evolving. A hundred years ago, it was a massive scandal for a woman to wear pants instead of a full length skirt. Where will we be a hundred years from now? Do you want to be on the forward edge of progress, or stuck in the past?