Columbine High School students held a solidarity rally Monday, celebrating the resumption of their classes on the Denver-area campus. Four months ago, the more than 2,000 teens were mourning the worst school shooting ever -- one that caused President Clinton to suggest reviews of everything from cliques' cruelty to the entertainment industry's voluntary ratings system.

The latter attack prompted less-liberal applications of "restricted" ratings as well as the requisite parental approval for admittance. It also removed the silencer from outspoken Harvard Law professor Alan Dershowitz.

"Teenagers are probably influenced more by ... mainstream representations of, and responses to, violence than they are by the extreme depictions on the big screen that are the object of the president's wrath," he wrote in a July column for the Chronicle of Higher Education.

Dershowitz, a former O.J. Simpson attorney, discussed representing a production company in the mid-'90s when it challenged NC-17 ratings of the movie "Kids" -- a pseudo-documentary about unprotected sex among teenagers. But he couldn't convince the internal appeals board of the Motion Picture Association of America that "Kids" sent a "powerful message about the dangers of promiscuity."

"If I had had teenage daughters or sons, I would have wanted to be able to take them to see the film," the civil-liberties expert wrote.

Ironically, Dershowitz initially had encouraged the creation of an NC-17 rating, because he thought theaters "would treat it more like an R than an X rating." The X rating had become a symbol of skin flicks, while rated-R movies didn't permit more artistic depictions of sex, he explained.

Since the NC-17 rating was added about a decade ago, though, most movie studios have avoided it because it lowers profits by limiting viewers and mainstream acceptance usually. Children under 17 can't see a show, even with a parent's approval.

This summer alone, producers of "American Pie" and "Eyes Wide Shut" have self-edited and barely squeaked past industry censors to get an R.

Movie theatre manager Paul Yeequee enforces the laws that prohibit teenagers from sneaking into such mega-hyped shows. At the AMC in Miami where he works, moviegoers are carded twice -- when buying a ticket and upon entering one of the 24 theaters.

All AMCs use these procedures, and the laws have been on the books for a while, he says. Some cinemas just choose to exercise restriction selectively, as Dershowitz predicted.

"It's good to be strict," Yeequee says. "First of all, the parents may not know what their kids are seeing."

Yet he doesn't remember any NC-17 movies showing in an AMC theater in the four years he's worked there.

Some like Florida State University film student Jennifer Jarvis could care less whether movies such as "American Pie" ever make it to screens.

Then again, the 20-year-old detests "body humor" and says she is family-oriented, unlike "most people (her) age."

Pursuing a fine-arts degree from FSU's ninth-ranked film school, Jarvis says her classmates and many current directors don't think about what types of films audiences want. She says neither gratuitous gags nor violence serves viewers well.

"If you're making a film that you refuse to let your own children see, then there's a problem," she says.

Jarvis says she respects her classmates' divergent aesthetics and opinions, but doesn't disagree with the president that the Littleton massacre was a wake-up call.

"(Without enforcement of the ratings system), you're going to see some people who are growing up in a world where there are 6-year-olds who are watching 'Natural Born Killers,'" Jarvis says with exasperation. "That's going to screw you up a little bit."