Consider for your analysis: if you're walking in the same neighborhood, even for many many walks, those walks' risks will actually be quite correlated. So it's not like the probabilities combine the same way they would for independent random samples. The vast majority of children could not force an abduction to happen to them in their life even if somehow they spent all their waking hours outside. Thinking the probability approaches 1 is pretty absurd, and I suggest reflects some poor probabilistic thinking.