Although the rank-and-file seem not to understand it, ease of access does NOT negate laws governing theft. In some cases, in some areas, it does mitigate the circumstances (a car driver leaving keys in his vehicle can be charged as an accessory to theft) but the law stands clear: steal, regardless of the access situation, and you can rightfully be charged for it.

Your DVD example is very poor and if you think it is relevant you haven’t thought it all the way through. No one has a right to even enter your domicile without permission, period (unless it’s the police with a warrant), door open or otherwise. By the same token, even if a neighbor’s wifi is unsecured, they are still paying for it and unless they’ve given express consent to piggyback on it you just flat do not have the right to do so. Now, it could be argued that naming the access point something like “Free Wifi for Anyone in the Area” could constitute consent, but maybe that goes without saying. ; )