You'll be curious to know how I first learned of the gang rape of a 15 year-old girl in Richmond, California.

A few days ago, the blog for The New Agenda, a women’s advocacy organization that I helped co-found, got hundreds of hits from search engines looking for " gang rape teenage girl.” Regrettably, our stories show that the Richmond attack, while horrific, is not an anomaly. Young women are more vulnerable to violence than any other age group.

Parents beware: Our daughters are in danger and the statistics are staggering. And as details emerge about the two-and-a-half hour episode, we must use the Richmond case as a teachable moment on gender-based teen violence.

Here’s what the Richmond case signifies, plain and simple: Gender-based assault has become an acceptable norm in our country.

Of course, as usual, our media screwed it up. A major cable network grouped the Richmond case with other attacks on teenagers—males and females—and attempted to make this a youth-violence issue. The print media set out on its victim-blaming mantra: “Sure, the victim was sober during the dance, but had she been drinking before the attack?” “She asked for it, right?” “It’s like the college girl who goes to hang out with one guy and ends up getting raped by eight…well, she chose to go to the fraternity.” Or like the media's search for what the pop star Rihanna could possibly have done to upset her mild-mannered ex-boyfriend Chris Brown that would make him almost strangle her to death.

Here’s what the Richmond case signifies, plain and simple: Gender-based assault has become an acceptable norm in our country.

• Wendy Murphy: Why Bystanders Should Be PunishedA not-for-profit group called Parents Television Council released a report this week titled "Women in Peril." The shocking findings: From 2004 to 2009, incidents of violence on prime-time broadcast television increased 2 percent; in the same period, scenes of violence against women increased 120 percent. And, the kicker: There was a 400 percent increase in the depiction of teen girls as victims.

No wonder the rape onlookers in Richmond were enjoying a free look-see while they filmed with their cell phones. It's just like sitting at home in the den—watch a few broads get knocked around on the tube, then run down a few "whores" in a video game, glance at a few half-naked girls in a magazine, and then pick up the cell phone for some afternoon sexting.

This is a wake up call, parents: Our teenage girls are in danger. Nearly half of teen girls who have been in a relationship say they have been victims of verbal, physical, or sexual abuse by their boyfriends. And if you are reading about the Richmond case and thanking goodness that your daughter is home safe, think again: One in five girls will be raped by time they are 24 years old. Richmond's church-going honor student, who was attacked on her way home from a homecoming dance, could be your daughter next.

So here's a challenge to the White House: Let's use the Richmond case as a teachable moment. Wouldn't it be incredible if our President would give a speech on escalating gender-based teen violence—just as he pounced on Gates' Gate for a teachable moment on race? Or perhaps our First Lady or Valerie Jarrett, Chair of the White House Council on Women and Girls, could open a national dialogue on what is happening to our teenage daughters.

In the interim, here's a call to action for moms and dads: It's time to talk. It's time to sit down with our sons and daughters and explain what is, and what is not, acceptable behavior (and there are many references to help). And next week, send a letter to the principal at your children's middle school or high school to make sure teen dating violence is in the curriculum. This we can do immediately and become our own grassroots force of change.

And the longer-term solution is this: Elect more leaders with a sensitivity to the issues surrounding gender-based assault. A state senator in New York told me in a radio interview that the best way to tackle the crisis would be to elect more women. As if to underscore her point: When NY State Senator Hiram Monserrate refused to step down after being found guilty of misdemeanor assault connected to slashing his girlfriend's face, it was NY State Senator Liz Krueger who led the charge to try to force his resignation. And she was followed closely by Senator Kirsten Gillibrand, who was also an early voice for Monserrate's resignation.

Silence is the great enabler of gender-based assault. As our country notches yet another gang rape, we must all start talking.

Amy Siskind is the President and Co-Founder of The New Agenda, an organization dedicated to improving the lives of women and girls. Ms. Siskind has appeared on CNN, Fox, and PBS. Ms. Siskind also writes for HuffPo and MORE.