Fearing that your child will be stolen by a stranger is ludicrous.
Well, almost. I remember one case in Finland where a stranger took a baby who was sleeping in a pram outside.
It was such an uncommon occurrence that it made national news, although the episode took only a few minutes and no one was harmed. Touching someone else's baby who is sleeping out is just a no. (Looking at it to make sure it's well is OK, of course). But some fear about this is understandable. Parents worry about everything, sometimes not very rationally.
Mostly this is about trust within society. Finland is still very homogeneous, people share the same values, and the level of trust among citizens is high.
Almost every "child abduction" report is actually a custody dispute. Fearing that your child will be stolen by a stranger is ludicrous.
I recommend reading the "Free Range Kids" blog/book, by the way. It may help you see past the media distortions.