In the UK, about 5% of children have been sexually abused. Nobody wants to risk that happening to their children and it's mostly perpetrated by people known to the children, so trust is understandably at an all time low.
Right, but parents don't trust anyone in the community, so stranger danger teaches kids to avoid any adults outside the immediate family and it's not unwarranted. For every Madeline McCann, there are literally millions of children abused.