i recently heard this story and it really made me think twice.
dont know if its true, never saw it in the papers or anything.
a mother in lanarkshire lives with her dad and her toddler. the mum went shopping and so her dad was looking after the 2 year old. the dad said to toddler 'grandads going upstairs for a shower i wont be long' and he did. when he came down there was no sign of the toddler, he looked out the window and a man was running down the street with toddler under his arm. he managed to stop them and called the police.
turned out the man who had snatched the child was a convicted paedophile who had chanced by the house and seen the toddler in the house on her own and just walked in and picked her up.
i now lock my door at all times and its really frightened me. its sad though cos i used to leave the door unlocked so friends and family could just come in and out.