So, here are some more rules. Don't let people in your house for any reason. Be firm with people. They are used to hearing no and will try to wear you down. Finally, watch your stuff.
People shoplift at yard sales just like anywhere else.
I've been an avid yard sale shopper for years and find that most of the time I've felt safe and have never seen anyone steal anything. Of course, I wasn't watching for a theft either, I was too busy trying to find a pair of boy's size six jeans with no holes in the knees. Oh, and one more thing. One driver was slowing down for the sale and was hit by another. Drive carefully when entering and exiting the street in front of a home with a yard sale.