Bullying has existed for centuries and likely dates back to the dawn of mankind. But in recent years, speaking out against it has become a rallying cry for parents, educators and celebrities from Ellen DeGeneres to Lady Gaga. The 2010 suicide of gay college student Tyler Clementi was just one high-profile case that struck a chord with many people.

"Bully," which opens on Friday and was directed by Lee Hirsch, follows five kids and families over one school year, looking at the issue and how it has impacted their lives. Stories include two families in which kids have committed suicide and one mother awaiting the fate of her 14-year-old daughter who was jailed for bringing a gun on a school bus.

While the extreme outcome of bullying is suicide, as in the case of Clementi, other effects include the loss of self-esteem, troubled relationships, depression and self mutilation.

The movie reaches theaters after stirring a controversy over its initial rating that restricted people under 17-years-old from seeing it without a parent. It is now being released unrated. But beyond the rating, bullying is a growing problem in part because technology has given today's youth more ways than ever to torment others, experts said.

Using cell phones and computers, kids send immediate, nasty messages via texts or posts on social media websites. And many experts see the Internet as a new school playground where kids gather to share information, post pictures and trade gossip.

"Today, bullying is 24/7," Ross Ellis, founder and chief executive officer of STOMP Out Bullying told Reuters. "It's at school, you go home and it's on the Internet. It's there all the time."

Julie Hertzog, director of parental training group Pacer's National Bullying Prevention Center noted a direct correlation between what's happening at school and online.

"They're not exclusive to each other - they're happening synonymously and heightening the experience," she said.

Currently, one out of four kids is bullied and as many as 160,000 students stay home from school on any given day because they are afraid of facing their bully. Each month 282,000 students in U.S. secondary schools are physically attacked, according to STOMP out Bullying.

When it comes to cyberbullying, 43 percent of teens and 97 percent of middle schoolers say they have experienced it. Fifty-eight percent of them do not report it to an adult, according to the STOMP out Bullying group.

EDUCATION AND TECHNOLOGY

Ironically, however, education, technology and the Web may be the very things that can have a hand in diminishing bullying, said "Bully" director Hirsch and others.

"When I was a kid, when a teenager committed suicide, the connection wasn't drawn to bullying," the 39-year-old filmmaker said. "Now we learn very quickly in the wake of these tragedies because kids will go on Facebook and start writing about what was happening."

Dr. Joel Leibowitz, an L.A. based psychologist who deals with children, teens and issues involving bullying, told Reuters that parents, teachers and administrators no longer can risk the belief that bullying is a rite of passage or that kids will work out problems among themselves. And he thinks the public's attitude toward bullying is starting to change.

"Educators and professional are now aware that there are serious, long-term consequences to bullying," he told Reuters. "It's considered to be a trauma, so you can think of post-traumatic stress disorder as a consequence of bullying. That can really be a problem for individuals and for society."

Hertzog believes the documentary "Bully" could help be a catalyst for change, calling it "an amazing opportunity for dialogue" while Liebowitz feels it can "bring people to a greater sense of awareness" about the issue.

Director Hirsch is hopeful, too.

"I actually think we're on the cusp of a profound tipping point towards the positive," he said. "People are talking about it and that's meaningful. That's how change happens."

Liebowitz said there will always be some element of bullying in society because it is human nature for some people to be bullies and others to feel bullied. But, he added, the behavior can be moderated through education.

"Kids can be taught to learn how to deal with their feelings and not have to act upon them," he said. "That would translate to future generations learning from those who have been taught in this generation."

(Reporting By Zorianna Kit; Editing by Bob Tourtellotte and Jill Serjeant)

• A Permanent Economic Emergency