If you leave your garage dor open, and go on vacation, you might just
get some of your stuf stolen... Wether the theif drove up in a car with
a tracable license plate, or did it with an Invisibility Cloak; doesn't
matter.
Do you really think it doesn't matter? In the real world, I think it matters a lot. Garage doors and houses aren't that hard to break into even when things are locked. As someone else pointed out in an earlier discussion, people lock doors while there's a big glass window sitting right next to it. The reason they can do that is accountability. If you break into someone's house, there's a good chance you're going to get caught.
That said, I think you've got to treat the internet entirely differently. If someone invents the invisibility cloak, you can be sure that home security systems are going to change drastically. For those who refuse to change, should they blame the person who created or sold the invisibility cloak? Certainly not unless they had some specific reason to believe the cloak was going to be used for a crime. Besides, it's much easier to protect yourself from criminals on the internet. Things on the internet are locked by default. If you don't plug in that ethernet cable, you don't have to worry at all. Any access to your computer systems is provided by you. I guess that's the idea behind the garage door analogy. If all houses were completely impenetrable except for the doors you create then the idea of invisibility cloaks wouldn't be nearly as scary.