I've been feeding this family of 5 crows for years. They have gotten comfortable enough with me that they'll come get snacks while I'm still sitting next to the food. I can call them with a specific whistle I use just for them, and they make a rattle noise (that sounds like the Predator) with me to thank me for food.

One late night I hear this horrible loud screeching. It woke me up, so I ran outside to see what it was. There was a guy trying to break into a window in my house and the 5 crows were dive bombing him screaming as loud as they could. He ran away.

So I guess I have guard-crows now.