There's not a matter of perception or culture as the candy was intentionally left out for a trick or treater to take. And since it's a well known holiday, the intent has been communicated.
If your door is open can I take a shower and cook a meal for myself in your house?
Lol. I don't know where you got this impression, but no, it absolutely is not.
Not only is it not, but you can absolutely be prosecuted and imprisoned for accessing those networks/servers without permission.
Furthermore, that doesn't really apply in this case because not only was he not given "implicit permission to use it", the in-flight WiFi system explicitly bars you from using the internet without paying for it.
Open WiFi is like a water fountain, or a bench, in a pubic place to me. There's no explicit sign telling you to use it but who'd put it there of it were not to be used? I'm in the UK.
So, for example if I'm out and about and there's an open WiFi I'll connect to it without seeking permission .. in fact I think it would be weird to go and ask (if you could work out who to ask).
(It's also very, very, very terrible practice for your own security. Don't do it.)
If you place a bench in public and you don't want anyone to sit on it then you need to notify people explicitly ... it's the same, I don't find the owner of benches and ask them.
Are there any attacks that work just by connecting to someone's wifi, obviously I'm only using it for non-sensitive traffic unless it's a recognised provider, it's certainly part of my security considerations. Are there specific attacks you're thinking of? Such attacks would work equally if I had explicit authorisation, of course.
Re your link, last time I looked it was allowed to have open shared wifi, and the way you indicate it's open for sharing is having it open and shared. That's probably why the police gave cautions, it placates the complainant and they didn't have to lose in court.
Then it should do so. If I connect and I can use the network without paying, that's not my fault.
I honestly can't believe we're even having this conversation. It is theft, period. Not only is it illegal, it's blatantly immoral.
It's not theft. It's not immoral either. Open wlan means exactly that, so where is the sign? You are on HN, so using something like a VPN is not uncommon, regardless of what network you are using.
The internet has different cultural norms than physical space. One-to-one analogies are useful for exploring those differences, but not for arguing what they should be. If I have a WiFi connection, leaving it without a password is implicit permission to use it. If I have a server that provides HTTP without authentication, that is implicit permission to access the contents.
That is not to say that people should take advantage of these social norms. If I find a bowl of car keys left on a front porch, even if it is Halloween, I should inform the owner of the house that they probably don't want to do that. If I find incremental IDs that lead to other customers' personal information, I should inform the company, and the other customers if necessary.