Yes, it doesn't matter how you try to explain it. The simple fact of the matter is if you don't want something stolen then you would protect it. Doesn't matter if its a car, money, house, possessions, you name it.
If you are too lazy to take the extra minute or two to store your car in the garage then you run the risk of having it stolen. There is no logic involved, it is all common sense.
Which means you're agreeing with him that it's fine to steal it when the owner isn't bothered about privacy?

I simply stated that if you cared for something you would protect it. Whether you like it or not the world is full of thieves so losing your possessions to someone else is likely to happen quite often.
Being as posting your information online is giving public access to said information and the whole matter of it not being illegal to gather that information there is nothing wrong with paying someone to find it for you.
My information, for example, is public knowledge as I allow it to be such. If I didn't want others knowing who I am then I would have protected that information and hidden it. If you cannot understand this then there is no help for you.