"SEX IN AMERICA" -- JOHN STOSSEL REPORTS ON ATTITUDES TOWARDS AND LAWS GOVERNING SEX, ON "20/20," FRIDAY, JULY 18 ON ABC

Sex today is everywhere, from television and movies to the internet to images in ads and even store windows. It's more in your face than ever before. But how big a problem is this? Or is it a problem at all? John Stossel examines sex in America: from attitudes towards sex in this country, to the laws our government makes about where we can have it, whom we can have it with and when we must be protected from seeing it. "Sex in America" airs on "20/20" on FRIDAY, JULY 18 (0:00-11:00 p.m., ET) on the ABC Television Network.

Sex Culture: Parents cringe watching television with their kids, says Peter Sprigg of the Family Research Council, a group disturbed by all the sex that's in the public square. "They [kids] are being exposed to sex and to talk about sex before they're even old enough to even think about having sex," he tells Stossel. With so many programs pushing the sexual envelope, Sprigg says he can barely find anything appropriate to watch with his young son. Stossel says he cringes too, but asks, "What's the real effect? Where is the damage? Sex is more prevalent than ever, yet rape rates, divorce rates and the percentage of teens having pre-marital sex have been declining over recent years. So isn't this good news?"

Dr. Marty Klein argues that some in America wage a "war on sex." "There are groups of people out there who are devoted to scaring the heck out of Americans about sexuality," he tells Stossel. "The truth is children think about sex whether we want them to or not. Children don't need our help to think about sex." Dr. Klein says, "American society attempts to restrict what adults can do, what adults can see, what adults can hear, more than any other industrial country."

Policing Sex: What happens when sex occurs in public? When actor Hugh Grant was arrested for having sex with a prostitute, he said he did "a bad thing." Police staked out a nearly empty park to arrest a man who, when a topless woman asked him to show her his private parts, complied. In Laredo, Texas, police arrested the Chippendale Dancers. In Alabama, legislators have banned the sale of sex toys. The punishment for buying a toy can be arrest and a fine up to $10,000 dollars, which is five times that for drunken driving. "You gotta wonder which one's more dangerous," says Sherri Williams, who owns a "romance" shop.

Polygamy: Peter Sprigg says, "Slavery and polygamy were the twin relics of barbarism� barbaric societies that we've tried to move beyond." But polygamy advocate Mark Henkel says the law is hypocritical. "Someone like a Hugh Hefner will have a successful television show with three live-in girlfriends. And that's all okay, and he's making great money, and that's all fine and great entertainment, but if that man was to marry them, then suddenly he's a criminal! That's insane!" He complains that the media is clueless because, after Warren Jeffs was arrested this year at that Texas polygamist compound, "the media kept saying, �polygamist leader, polygamist leader.' But the case actually involved incest and arranged marriage. [Yet] he wasn't called an incest leader. He wasn't called an under-age marriage leader." One Black polygamist with four wives says polygamy is a civil rights issue: "It was illegal for me to marry a white woman at one time. It was illegal for me to vote at one time. And if I had accepted somebody else's definition of what was right and wrong, I would still be riding in the back of the bus."

Predator Laws: In order to protect children from sexual predators, states have passed laws to try to keep molesters far away. But as Stossel reports, as so often happens with many laws, there are unintended consequences, as the predator laws cast a wide net. Take Frank Rodriguez, whose consensual sexual relationship with his high school sweetheart when he was 19 and she was 15 led to his being branded for life as a sex offender � even though the two ended up marrying and having four children.

Why We Cheat: America may be waging a war on sex, but that doesn't stop anyone from doing it. Infidelity is all over the news. Even America's most desirable women like Jennifer Anniston, Halle Berry and Christie Brinkley are reported to have been cheated on. Why? Are men programmed to wander? Steve Santagati, an advice columnist and self proclaimed "bad boy," says men are. "Do not go and think that you need to get married, have two kids and live happily ever after. That, my friend, is a load of crap for 90% of the population." Scientists confirm his assumption that men are programmed to cheat, and that even animals once thought to be monogamous are cheating. But Dr. Scott Haltzman, who wrote The Secrets of Happily Married Men, points out that couples can be faithful, and when they are, they are happier. He says "the relationship you have with your spouse cannot be replaced by any affair or any fling."

"20/20" is anchored by Elizabeth Vargas and John Stossel. David Sloan is executive producer.