A lot of people online talk about objectification-- specifically, sexual objectification qnd treating women as sex objects-- but a lot of people also don't really seem to quite understand what objectification and sex object actually mean. It doesn't mean looking at a woman, and thinking she's sexy. It doesn't mean noticing her breasts, or hips. Hell, it doesn't even mean fantasizing about sex with her.
It means treating her as if she is not a full person, and as if her primary purpose is for sex, to give men sexual pleasure. It means treating her as an object for sex-- the way a vibrator or lube is a sex object, the way a game controller is a gaming object, the way a cane is a mobility object. It means treating her or seeing her as an object that exists for sex.
That isn't the same as seeing her as an awesome-- or awful-- person that you might want to have sex with. It isn't the same at all. And understanding the difference can help people understand why it is that feminists object to women being treated-- by people or the media-- as sex objects. Because honestly, people can look at each other and evaluate each other as potential sex partners all day long without seeing them as sex objects-- as long as they also stay cognizant of the fact that that person has their own inner life and mind, and that they have qualities that go beyond what sort of sexual experience they'd give, or what sort of sexual thoughts their image evokes.
Ads turn women into sex objects when they pose women sexily to sell things-- because her sexual appeal is the only thing about her that matters. Some men do this too, when they think the only reason to talk to women is as a preliminary to getting her into bed. But thinking about sex-- in conjunction with thinking about her intellect, or musical abilities, or even just personality-- is not the same thing.
I've seen on some blogs men who misunderstand this, and angrily defend their rights to fantasize about sex with women they meet. Well, fine. Fantasize. Some people (myself included) find the thought of strangers or even friends fantasizing about them to be creepy and unwanted. But it doesn't necessarily have to dehumanize them, as long as they still think of her as a real, full human being. Modern feminism is not trying to take away anyone's ability to fantasize. We're just saying that, in the way you think, in the way you interact, int he way you fantasize, in the way you have sex-- remember that women are people, not things, and that they have the same emotional depth and potential that you do. It's not much to ask, really-- but man, does it get a lot of resentment from some people.