Did the home owner invite you in? No? Then why try the doorknob? Connect only to WAPs with direct approval.

Did you pay for it or was it a gift? Neither? Then it's not yours. Pay for what you take and make sure the rest is free or a gift.

Do you lock the doors to your house? Then why not lock down your network? Whether or not you have valuables isn't the issue.

Do you leave the keys in the ignition and engine running when you walk away from a car? Then why would you do this on a computer? Log out or power down.