I have a non-Ring doorbell camera and while I can't prove it has deterred theft, it's pretty useful in at least:

* Getting a partial face/partial vehicle ID of someone who stole our package

* Seeing the sneaky method in which they stole the package (allowing me to talk to neighbors warning them about the method used)

* Getting a private instant announcement of who exactly is at the door (if they've been here before and they're in my contacts)

* Notifying us while on vacation that someone out of the ordinary is at the door (and being able to speak to them as if we were home)

* Deterring raccoons (bright light on the front of the camera)

Not-so-useful things:

* Seeing the large number of cars that like to use our driveway to make a U-turn

There is an option to turn off audio recording and all footage is encrypted.