Are you watching what your kids post?

You never get a second chance to make a good first impression. This sage advice has served young people well over the centuries, but it is taking on new meaning in the Internet era. Kids and teens who eagerly post personal information and thoughts on various blogging and social-networking sites are leaving a digital trail that can have serious implications for their futures.

Much of the recent discussion about teens and blogging has focused on dangers from predators, or on constitutional rights and free speech. There has been a rash of school suspensions and arrests for Web postings used by junior high and high-school students to defame others or paint wild pictures of themselves. Boasts about drug dealing have even led to actual drug busts

The content itself--despite whether the courts eventually decide that it is entitled to constitutional protection--can ultimately limit our children's opportunities. After all, the easiest way to check people out these days is to hop online and do a few searches.

We are still quite naive as a digital culture, and young people are finding out that what you put up on the Web can still be following you around 10 years later.

Kids who get mad at a teacher and rashly publish a scathing and obscene lampoon on a site like MySpace.com aren't thinking that it could prevent them years hence from getting a scholarship to college or obtaining a job they really want. But this can and has happened. One recent law school graduate was shocked to lose out on a prestigious clerking job for a judge when a routine background check turned up something the candidate had thoughtlessly published years before.

We are still quite naive as a digital culture, and young people are finding out that what you put up on the Web can still be following you around 10 years later. Private conversations that used to take place among kids in homes or malt shops are now being recorded for posterity, despite whether the kids realize it. And even good kids may occasionally share comments that will cause them problems down the road.

The Internet seems very ethereal and transient, but the brick-and-mortar world pales by comparison, when it comes to storing and disseminating information. That is what computer networks were designed to do. Once you air your dirty digital laundry on the public Internet, you can't take it down and fold it and put it away. It is out there forever, accessible by search engines and completely beyond your control.

Concerned groups are lobbying for new laws that restrict what children can access and what they can say on the Internet. However, such legislation may well fail to pass constitutional muster, and industrious kids could probably figure a way around it even if it did.

One of the harsh realities of cyberspace is that free speech can be a very loose and very big cannon when wielded by teens and tweens. Research shows that the part of the brain that controls impulses and mitigates against rash behavior isn't fully developed until well into young adulthood. It is very good to educate kids about digital trails and the effect they can have later on, but it won't change this biological fact.

As adults, we have to be responsible for our words and actions, but as parents, we need to protect our children from themselves and their impulses. We provide safe places in the physical world for our kids to congregate and interact, and we need to do no less in the virtual world. On the public Internet, danger is always only a few clicks away.

Whether we are worried about pedophiles and cyberbullies, or about self-authored content that could brand our children forever, the answer is the same: We need a compelling and yet protected environment in which kids can create and share content.

We must come up with a closed ecosystem in which our kids can safely flex their digital muscles and develop the skill sets they will need in the Internet age. And we must think of the long-term implications if we continue to leave them to their own devices.