So your claim is that if I sit down at a computer that isn't mine and has no security measures in place, and then open a file, that I have legally "hacked" the computer?
The minimal definition you can fall back to is "unauthorized access". But now you have to establish and argue that an unsecured computer/system is off limits to everyone except the owner. Which then opens up a big can of worms with network connected devices, and demonstrates that such basic and literal verbatim interpretation doesn't work in reality.
