Hey... this is not the fault of Craig's List. You can find anyone on the Internet if you are looking. There are tons of chat rooms and love connection sites to choose from. It can definitely ruin a relationship and it should not be tolerated. If your loved one (especially a child) is spending more than a short time on the computer then you could have a problem. There is also software you can buy to spy on that person if you are suspicious. Some people may have an issue with that but hey - it is one way to nip it in the bud before it gets out of hand.
Parents should definitely have total control over their kids' use of the internet. It is obvious that there are thousands of sicko predators out there just waiting for the right moment to pounce. Be a support to your loved one - not a blind bystander!! Wake up people! Your relationships and your children are at high risk here.