People live under the false pretense that people can be trusted. People feel that a badge or title sums up one's personality, character and defines them as trustworthy - and this is a false assumption that will only lead to some child being hurt, or worse.
Doctors, Ministers and Priests, Teachers, Police Officers. Aunt, Stepmother, Nephew.
These are presumed safes. When you're in the presence of a Minister or a relative supposedly that person has the true safety and concern for your child in heart and they, sadly, don't always.
Not to say the majority of people are twisted - more people are safe than not safe, in my opinion. But that doesn't mean you can be too relaxed with your responsibility as a parent and comfortable with who associates with your children.
I'm always leery - especially of the people who seem overly friendly to my children but don't acknowledge my presence, first, and don't engage me in conversation when I'm there to discuss business (either it be a doctor or store clerk). . . people like that put me on edge.