Do you sign for your packages from FedEx and UPS?

I ask because, where I currently live, the UPS and FedEx men never knock on our door to drop off our packages. They always just leave the packages by our front door, even if we are home. Maybe I’m paranoid, but couldn’t someone just steal it right off your doorstep? Does anyone else have this “issue” with the package delivery service in your area?
Or am I just paranoid?