Wouldn't identifying them via MAC address be very inaccurate, as you can't pinpoint them to a specific house very easily?

Would cameras like these emit any sort of IR light or anything that might be detected from a distance?

Object recognition would depend on them being very obvious from the outside - which Rings do appear to be (I've never seen one in person) but I imagine there will be less-obvious options soon enough, if there isn't already.