If you are the parent of a middle or high school student, chances are your child is either engaged in, or witness to, online behavior that you would find distressing, if not shocking.

But for many teens, this behavior has become just another challenge of adolescence, and another aspect of their lives that parents either don't know about or feel ill-equipped in how to respond.

The existence of a generational divide between what adults and teens believe is acceptable communication on social media today is one of the findings of an in-depth look at how teens treat each other published last week by the Weekly.

The package of stories reveals the unprecedented struggles facing today's teens as they find their way in the unsupervised world of social media. Teens related stories about the silent suffering many endure when peers they consider friends anonymously post crude, sexually explicit and often completely false comments designed to hurt their feelings and gain social advantage at their expense.

For some, especially those at the top of the social order, it is just another tricky social challenge to navigate. But for those who are more vulnerable, being the subject of online bullying, teasing or gossip can be devastating and lead to depression, alienation and suicide ideation.

It is an environment significantly different and more mean-spirited than faced by teens just a few years ago, and is alarming educators, psychologists and law enforcement as well as parents.

In affluent, highly educated communities like Palo Alto, the dangers may be greater because many teens are very skilled at being polite and engaging with adults when they need to, yet behave very differently on social media when dealing with their classmates away from adult eyes.

As one Paly senior said, "Teens know how to put their best foot forward in front of an adult, especially at school."

That skill, which leads many parents and teachers to a false sense of trust about their teen's behavior, leaves many teens free to let loose, especially in tech-savvy Palo Alto, where kids at an ever younger age are way ahead of their parents' knowledge and understanding of online social media platforms. Often that includes making anonymous online postings, or posts to Facebook pages that carefully avoid identities but that convey a derogatory message or threat to those who recognize they are the intended audience.

When shown some examples of online postings by Paly students, former principal Phil Winston said "Not one of these young people would say anything like that in person. There's such power in not being able to see the person you are hurting."

Jim Steyer, founder of Common Sense Media and Children Now, wrote "We're witnessing the rise of new forms of damaging, destructive interpersonal behavior, like cyberbullying, that are facilitated by digital platforms. It's a lot easier to say or do something truly hurtful to someone else, without considering the consequences, when it requires only a few keystrokes on a computer or cell phone."

Gunn High School Assistant Principal Trinity Klein observed that social media has changed the way students relate to one another. One teen girl told the Weekly she intentionally avoided developing close relationships out of fear that a friend might turn on her and reveal personal information on social media.

Exacerbating the problem is that the social norm for kids who are the victims of online teasing or gossip is not to tell anyone, especially parents, act unaffected and just hope it will pass quickly. Some teens are more resilient than others, and those who are not often have nowhere to turn for support and comfort, leading to isolation and depression.

As the Weekly's stories show, parents, kids and school officials are all struggling to sort out this new environment. With the teens themselves saying that anti-bullying and cyber-education programs are ineffective and not taken seriously, experts believe the focus needs to be on reaching kids when they are younger, before age 12, when they are typically opening Facebook accounts and beginning to use social media. The opportunity to influence social norms of teens closes, they say, during middle school, making the late elementary school years the prime time for parents and teachers to explore these issues with their children.

Lots of efforts are underway in the schools, beginning in second grade, and a small Palo Alto start-up, My Digital Tat2, is currently working with Palo Alto fifth graders and parents on raising awareness about kindness and respect online.

As with so many other things teens are drawn toward that involve potential harm, parents need to walk a fine line between rule-making and understanding the allure. As some of the teens themselves acknowledged, they know when they are crossing the line with their online behavior. The challenge is to make it socially more powerful to stand up and object to such behavior than to engage in it.

Editor's Note: You can access the Weekly's August 16 cover package on social media, entitled "Power to Hurt: How Social Media Impacts Our Kids" here.