Being in a democracy, it's usually a matter of majority rules. That said, I'll respond to your last question: "Do you think more people should do something, and what can we do as parents, people that are tired of putting up with it?"
If a person were to stand in front of you, and open a trench coat, and start fondling himself, have you just been exposed to nudity, to pornography, or whatever? How would you go about stopping a person from doing something like this on a spur of the moment situation? Granted, the person perpetrating such an action has an intention in mind, but the person caught in a situation to have to view such a thing didn't have an intention of being outside to see it. Follow?
The same can be said for billboards, or watching TV. Boy, TV, that's a hard apple to fight. Look at "Big Brother" as an example. Every Thursday night, you hear CBS sponsor July Chen promote Showtime 2 After Dark. And the show itself has activities for the participants whereby the women parade around in bikinis, and the men where bulge-tightening spandex. And this is considered "family-TV". First you watch it, then you're invited to watch even more "uncensored" TV.
I'm not the type of person to say, "if you can't beat em, join em". The battle isn't impossible to win. It's just a much huger monster to beat these days. Even our own constitution guarantees us the Freedom of Speech, and the Supreme Court has declared pornography in all it's glory to be an expression of that freedom. What do we do?
We teach our kids, and that's about it. Where do you want your kids values to be? Where do you want them to be grounded in terms of their values? Once you've done your part, then it becomes a matter of your kids choosing - yes, they have a choice - where they wish to exercise their voice. If we as parents have done our part to teach them, we cannot be responsible for the actions they take thereafter.
To change things on a grander scale? Simple. Get involved - like David Scwimmer. Sometimes, just speaking up is enough to start a snowball effect. In this case, it's gonna take a LOT OF VOICES - be it stars, or whoever - to get a snowball effect started. This topic is just one small part of it. So congrats, you've done your part in getting the topic rolling.
Mike