I have hereby been whooshed, though in my defense I have a guest-only, throttled and isolated wifi network so the potential for misuse didn't occur to me.
I have exactly the same. I don't want the entire world to use it though, as it still uses my broadband connection, which contains my external IPv4 address. I guess I should tunnel it over a VPN instead.
Pretty sure only people who know where you live can use your wifi network, and only then when they are in range - not the entire world.