Lots of parents don't think it through; they're convinced that having their kids' fingerprints taken is some kind of a hedge against abduction. The faulty reasoning is, "if someone steals my child, the fingerprints will prove it's mine and I'll get it back!" The fault in that, of course, is that if you need fingerprints to identify a child, it's either because the child is too young to identify their own parents, is non-verbal due to a condition such as autism, or because the child is dead. But parents simply don't think that way. They just think, fingerprints = safety.