Everyone wants to know how many predators are online and how likely it is that their kids will be victimized. People who aren't online think that the problem is bigger than it really is, and many experienced Internet users usually think it is smaller than it really is. While we do have some statistics about actual investigations and arrests, they aren't an accurate measurement of the real problem. No matter how hard we try to quantify the problem, we fall short because so few of the incidents with cyberpredators are ever reported to law enforcement.

Based upon discussions with the cyberlaw enforcement agencies I work with, here's what we do know: In the first year since its launch in March 1998, the National Center for Missing & Exploited Children's CyberTipline took in more than 1,000 complaints involving online enticement of children by adults for offline sexual purposes. That number has grown fourfold.

Based upon what we know and what we hear, this is happening worldwide, and in the U.S. last year there were approximately 4000 cases where law enforcement opened a case involving attempts to entice children into meeting sexual predators offline. You will be happy to know that almost all arrests lead to people going to jail. The FBI and U.S. Customs prosecutions in the United States, and prosecutions in the U.K. and in Canada have approximately a 99 percent success rate!

In the United States alone, there are approximately 29 million teens and children under the age of 18 online. Roughly half are 13 and over. For there to be approximately 4000 annual cases, out of a potential 14.5 million users means your children are pretty safe online.

But reported cases isn't the whole answer. We have learned, through surveys, that at least 12% of the teen girls polled admitted to meeting Internet strangers offline. Family PC Magazine, although no longer being published, surveyed teenagers and found in 2001 that 14% of the boys polled and 24% of the girls polled admitted to meeting Internet strangers offline. When we conduct informal polls at schools, we learn that the percentage of teens over 13 that admit to meeting Internet strangers offline is always at least 13%.

What does this mean? It means that our teens are meeting strangers offline. What percentage are predators and what percentage are cute and wonderful teens (as hoped for when our teens meet them offline)? Who knows? The best answer is "too many."

However, no matter how we crunch the numbers, if something bad happens to your child, the statistics are meaningless. Even if it happens to only one child in the world,  that's one child too many.

Parents may say, "I use the Internet all the time and I never see any problems. I don't see how my child chatting with strangers online could create any serious threat. It's only talk, after all. Am I right?"

Chatting with strangers, as long as your child doesn't share personal information with them, or try to meet them offline may be harmless. But let me show you how easily the problems arise.

Most kids know not to share personal information online, but certain kinds of information come out during the course of conversation--things that, on their own, don't pose many risks, but when put with other bits of information allow someone to find your child. These are facts that our kids wouldn't think twice about sharing.

Some parents say, "O.K., I have put my computer in a central location and my children can only use it when I am home to supervise them. What happens when they go next door to their friend's house?"

That's one reason I keep harping on teaching them how to make good choices and use the filter between their ears. You can't be everywhere always. But, you can do something more when it comes to their friends.

Reach out to their friends' parents and talk to them about your concerns. Make sure that you and the parents of your children's friends are in agreement about monitoring the children's activities online, and that you use similar tools to enforce your choices. If not, circumventing your parental controls is as simple as your children walking next door and computing at a friend's house. If you can't agree on a joint policy, make sure the other parents honor your wishes and keep your children off their computer while visiting. It's a matter of respecting your role as a parent. Make sure you do the same for them.

Parry Aftab is a noted online safety and privacy expert, and Executive Director of WiredSafety.org.