As far as I understood, the attack vector is different. Entering the ship is useless, there are no controls for humans.
It also likely affects international treaties regarding the obligations of the master or officer in charge.
If the computers go down, and with no one aboard, is it considered abandoned? Can anyone claim salvage rights by hooking up a tow?
Currently, "vessels have an international duty to give reasonable assistance to other ships in distress for saving lives" (quoting https://en.wikipedia.org/wiki/Marine_salvage). How does that duty extend to uncrewed vessels?
I'm sure there are lawyers salivating at the chance to resolve these questions.
The fact that there's no driving wheel doesn't mean you cannot take control of the ship if you can plug your stuff to the right port.