Dan Radcliffe, Nude on Broadway—If You Care.

You'd expect a lot of parents to get on their high horse about Daniel Radcliffe's role in the Broadway revival of "Equus," which opens this week. How could the actor who plays Harry Potter—hero to millions of young, impressionable children—get naked onstage, and in such a fiercely disturbing vehicle? Radcliffe plays Alan Strang, a disturbed young man who, when the play opens, has been sent to a psychiatric ward because he blinded six horses with a poker. In the play's climactic scene, Strang's doctor contrives to get the young man to re-enact the brutal act, which starts with an explicit sex scene and ends, after about 10 minutes of running hysterically around the stage, with the horses. Radcliffe does the entire scene nude. Naturally, photos of Radcliffe hit the Internet soon after the show opened in New York, with the headline WHO WANTS TO SEE DANIEL RADCLIFFE NAKED? But the funny thing is: no one really seems to care. There have been no complaints, no protests or boycotts. Or even much commotion at all.

What happened to nudity? The Internet, which has made pornography as accessible and ordinary as a rerun of "I Love Lucy," is obviously a supporting player in this scenario, but you could make the argument that this moment is years in the making, with each flash of flesh diminishing our fascination. "Equus" is actually the second major stage revival this year, after "Hair," which when it debuted in 1968 was the first Broadway show feature nudity. In 1970, censors tried to ban the hippie-love musical in Massachusetts, until the Supreme Court overruled them—but this year, parents giddily took their tweens to performances in Central Park. You could argue that the last time nudity became a cause célèbre was when Janet Jackson's breast made a surprise appearance at the 2004 Super Bowl. "The Britney Spears generation walks around with exposed midriffs and amplified breasts," says the social critic and feminist Camille Paglia. "Who cares?! Being surrounded by plasticized Barbie dolls, nudity does not have the slightest meaning whatsoever."

It didn't used to be this way. While nudity and celluloid go hand in hand—one of the first major motion picture that showed a woman fully naked was the 1914 silent film "Inspiration"—Hollywood was for a long time afraid of threatening American values. If the movie industry was labeled religiously bankrupt, box-office receipts would flounder, particularly among members of the Roman Catholic Church. In 1915, five years before Prohibition, the Supreme Court ruled in the case of MutualFilm Corporationv. Industrial Commission ofOhio that films weren't a form of expression protected under the First Amendment. Hollywood didn't want to be subject to local censors, so it established its own set of rules: the Hays Code, launched in 1934, which predated today's more lenient MPAA ratings system. Among its edicts: "Complete nudity is never permitted. This includes nudity in fact or in silhouette."

Nudity abroad was another question. For a generation of repressed men in the 1950s, Bridget Bardot represented uninhibited sexuality, appearing topless in a series of movies that were imported domestically in elite art-house theaters. At around the same time, a series of Supreme Court cases slowly began to reverse Ohio—chief among them, 1951 ruling over an Italian film called "The Miracle," which showed a nude woman. The launch of Playboy magazine coincided with this shift in popular opinion, and a star was born out of a 1953 pinup named Marilyn Monroe. But it wasn't until 1960 that American audiences were titillated with the invitation to join a woman in the shower. The movie was "Psycho," and the actress in question was Janet Leigh. Alfred Hitchcock employed a body double, and the camera only shot at the naval, the shoulder, the back—the forbidden silhouette. It was enough to inspire shrieks, and a revolution. The female figure had come out from behind the curtain.

In the '70s , the MPAA tried to monitor explicit nudity by introducing the X rating. But by 1972, the X-rated "Deep Throat" had so infiltrated popular culture, it became the nickname of the mysterious Watergate informant. Suddenly, you couldn't find a reason for people not to get naked. In 1974, a streaker crashed the Oscars. Horror movies targeted to high-school boys, such as 1976's "Carrie" with Sissy Spacek, invented excuses for babes to strip down. The '80s became the "Porky's" decade. Sharon Stone owes her career to the scene in "Basic Instinct" where she slowly uncrosses her legs and it's clear that she forgot her undies.

TV didn't want to be left behind, so in 1993 "NYPD Blue" was the first series to shoot its female stars from the chest up and its male stars from the bottom down. And there were lots of bottoms, most famously the one belonging to portly Dennis Franz. (David Caruso's nude scene in the pilot caused such a stir, that some local stations never aired it.) "Titanic," the 1998 Oscar winner, went on to become the highest grossing film of all time—with the classic scene where Leonardo DiCaprio paints Kate Winslet topless. It wasn't the first PG-13 movie to show a woman's breasts, but it was the most popular.

The final frontier in nudity was male, which apart from Michelangelo's "David" was a taboo in the arts until recently. Richard Gere broke a barrier with 1980's "American Gigolo" as the first mainstream heartthrob to appear fully nude in a big studio picture. But theater was probably where it became normalized. In 1994, The Washington Post ran an article about more nudity on stage, fuelled by dramas about the AIDS crisis—like "Angels in America" and "Love! Valour! Compassion!" where the entire casts goes skinny-dipping on stage. A 2005 survey in The New York Times found that in the previous 15 years, 25 plays featured full frontal nudity, and 40 of the 50 naked people in those plays were men. It was only then that Hollywood caught up, as homophobia waned and male actors took bigger risks. Among the most daring is Viggo Mortensen, who played an entire fight scene upon losing his towel in a steam bath in last year's "Eastern Promises." This year, Jason Segel lost his towel, too, in "Forgetting Sarah Marshall," though his nudity is played for laughs. Even Bart Simpson drops his shorts in "The Simpsons Movie." When Daniel Radcliffe does it onstage, it doesn't seem risqué anymore. Actually, it seems quaint.