As I wrote in my column two weeks ago, marketers are out to get America's youth, and they'll stop at nothing in the name of "entertainment" to do it.

Parents take note: The only thing that stands between your kids and those who seek to exploit them for the sake of the almighty dollar, is you.

In order for you to be successful at protecting your kids in today's media-saturated culture, you must never, ever underestimate the power of the forces arrayed against you. An episode of the PBS program "Frontline" titled, "The Merchants of Cool," spells out the lengths to which marketers will and do go to manipulate our children into buying their products. This amazing documentary should be required viewing for any parent who believes that MTV is just plain ol' entertainment for today's teens.

As the host of "Merchants of Cool" says, the way to get money from today's teens is to create programming that, "grabs them below the belt and reaches for their wallet."

The competition for our teens' wallets is fierce. Five companies - News Corp, Disney, Viacom, Universal Vivendi and Time-Warner - fight continuously for the space in teens' brains and the $100 billion they spend every year. These five companies control all the major film studios, all the TV networks, most of the stations in the top TV markets, much of the radio we hear and all or part of every major cable network.

The master at feeding crass images of sexuality and rebellion to our children is Viacom. If the name of this media giant sounds familiar, it's because they are the same folks who brought 90 million Americans Janet "Flashing" Jackson during Super Bowl 2004. While CBS whined it had no idea MTV was going to produce a show that included what amounted to a strip-tease act, the execs of the parent company of both broadcast outlets, Viacom, were laughing all the way to the bank.

When it comes to creating programming for teens, the "Merchants of Cool" explains how MTV controls much of the culture in which America's teens now live. Through all the focus groups, all the grilling of teens about their interests, all the study done of today's youth - including visits by MTV executives to the homes of typical teen viewers - all the "culture spies" it dispatches to see how successfully they are impacting their target audience, the corporation has figured out not what teens want, but how they think. This most insidious use of marketing doesn't seek to satisfy the needs and desires of a mature customer - it seeks to manipulate young, impressionable minds and influence their values and lifestyle.

One result of the MTV market research is the creation of a female and male character that are now seen in various forms in all MTV programming. The male image is known as a "Mook" to industry execs, and the female is referred to as a "Midriff."

Mooks are caricatures of modern teen boys. Sort of. They are models for them to aspire to. Sort of. They are wilder and bolder and ruder and cruder than the average teen boy, but they are designed to keep our sons hyper and addicted to watching the aberrant behavior so that ever more ads can be pushed their way. They are the obnoxious pro wrestlers, the death-defying stars of the "Jackass" TV show, and the guys on MTV's Spring Break specials belching and dancing crazily with scantily clad women they met 10 minutes earlier.

They exemplify perpetual adolescence living on the edge. They seem to say: We get away with it - do what we do, look as we look - and you can, too.

"Midriff" is the name given to the female icon created by MTV. The character is personified by the sexual bad-girl Britney Spears and dozens of other Britney look-alikes who dominate the airwaves. The "role-model" teaches even preteen girls it's time they embrace their sexuality and learn how to use it to their advantage; the message is that girls are sexual objects and their sexuality is their power. That's why America's little girls are now baring their bellies and strutting an attitude in malls and in schools around the country.

If you've fallen into the trap of letting Susie or Johnnie go to their room to watch MTV for hours on end, it's time to set your kids free from the machine that is using them. I urge you to start by ordering the " Merchants of Cool" and watching it with your kids. Showing them exactly how they are being manipulated is a powerful tool.

A final warning: You may be shocked by some of the images in "Merchants," but if your kids watch MTV, they won't be. Things have really gotten that bad.

Rebecca Hagelin is a vice president of the Heritage Foundation.