Terrible analogy. You have permission to read books in a library.

Forgetting to lock your door isn't granting permission to people enter your house, and it doesn't grant people permission to take your valuables. It may be neglectful to leave your door unlocked, but it doesn't imply granting permission to enter your house.

Same goes with computer security. Leaving your computer insecure may be neglectful, but it does not imply someone has permission to take your data.