America is raising a generation of children on porn - and your child just might be one of them. According to the London School of Economics, nine out of 10 teens who go online will view pornography. The Kaiser family Foundation reports that 70 percent of those who viewed porn stumbled across it - many while innocently doing their homework - and had not been looking for it.

The purveyors of hard-core porn are so fixated on creating addicts out of our sons and daughters that they have made it virtually impossible for children to escape their clutches. Even one mistyped letter can lead your child into a sordid world where women are objectified, where there are no lines between violence and sex, and where the most intimate of human acts - created by God to unite husbands and wives - has been twisted into something abusive and ugly.

The negative effects of porn usage on children are clear. A Heritage Foundation study reports that the harms include: overestimating the prevalence of practices such as group sex, bestiality and sado-masochism; perceiving promiscuity as normal; developing cynical attitudes about love; and viewing the idea of raising children and having a family as unattractive prospects. Another horrible consequence is that boys begin to view girls as nothing more than sex objects, and our little girls begin to think that being one is how they get ahead in the world.

The solution to a huge part of the problem is easy: download a reliable Internet filter. If you as a mom or dad are not intentionally building a protected space for your children, they risk being mentally and emotionally captured by pornographers in the safety of your own home.

Today's wonderful technologies such as the Internet have many benefits for our children - the world and all its wonders are magically at their fingertips. But these advances also mean that parents have to be proactive in fighting those who misuse them. We must not sit idly by when our children are being targeted.

The great news is that it only takes a few keystrokes and a few minutes to download a filter that will keep the scum out of your house. I've researched many filters and have found several effective ones that I profile in my book - they all stay one step ahead of the pornographers and clever teens who try to figure out how to break through.

A particularly comprehensive one is offered by BSafe.com and costs only about $50 a year. The service is password protected, so you as the parent can simply override the block if it inadvertently screens out something you need. It also sends you a private e-mail letting you know which sites people in your home attempt to visit.

This feature came in handy for me when we had a sleep-over of teenage boys one night - it seems that one of them got up and tried to visit his favorite porn site. That information alerted me, and I was able to make sure his parents knew he might have a problem they need to deal with.

Critics argue that no system is foolproof. That might be true, but a filter can help you stop the vast majority of the pollution from infecting your home. Of course, you as the mom or dad should be the ultimate filter. And with the help of a reliable filter that you install right away, your job will be a lot easier.

The bottom line is that if you have the Internet, and you haven't installed a filter, then you are continually inviting perverts into your home to converse with your child. When someone knocks on our doors, we're selective about who we let in. Make the Internet follow that rule, too. And do it today.

Rebecca Hagelin is senior communications fellow for the Heritage Foundation and the author of "30 Ways in 30 Days to Save Your Family" and runs the Web site HowToSaveYourFamily.com.