VRBO is loaded with illegal rentals. Ditto for Craig's List.
Whether the person you contact is actually the owner of the property is another thing altogether, but just because they may own the property it doesn't mean that it's necessarily a legally permitted vacation rental.
Here are the addresses of all the LEGAL vacation rentals and B&B's on Oahu---if the rental you're interested in is not on the list, it's illegal, pure and simple.
http://dev.honoluludpp.org/Portals/0.../NUCreport.pdf
You can plug in an address here to find out owner info:
https://www.city-data.com/honolulu-county/
So if the rental is has a legal permit, it will be on the list, you can plug in the address and voila---there is your info.
If the place is not legal and you can't get an address from the "owner" then caveat emptor.
As far as thieves being able to target vacation rentals through published addresses? Well, maybe, but vacation rentals stick out like sore thumbs in our neighborhoods. A quick ride through Kailua and even a dumb thief would be able to scope out and zero in on vacation rentals quite easily. But yes, published addresses might make it a tad easier.