The other day I was looking around, and found MissingKids.com. It is a site dedicated to finding missing and exploited children in the US. They also have a sister site ICMEC that offers the same service for international missing children. I began looking into things like the amber alert system that anyone living in the US is probably very familiar with. Since I am now in Europe I wanted to know what the equivalent service is, and assumed there would be an EU-wide database. As of yet I have only been able to find Interpol's missing children register. Amber alert apparently has an 80% success rate.
[Update] In 2010 Ireland started talking about working on an Amber Alert system. I assume, though, this was swept under the rug with the economic troubles.