Someone I know had what could have been a home invasion attempt last night. There was a loud knocking on her door and when she went and called out "yes?" nobody said anything. They knocked loudly again. She asked, "who is it?" No response from the other side of the door.
She peeked out her living room curtains and saw three vehicles. One in the driveway and two in the street. She waited and before long the three people went to their cars and left.. one of them was folding something that to her looked like a blueprint.
I'm just glad she has good door locks and uses them. I'm glad she had good common sense and didn't just open the door. Scary situation to be in.