asking permission first - an analogy
To the people who are saying it is an offence even if the router is open because they didn't ask the owners explicit permission first - try this analogy.
When you browse the web you are connecting to someone elses resources, eg the el reg site - they have to pay their providers for the bandwidth costs of supplying news to you. So you are using their service which they paid for. Did you ask them permission to connect to the website first? No? Then you are committing an offence in the same way that the 'wi-fi leechers' did.
Oh wait a minute, you're not. You see, even though there is no explicit permission given anywhere on this (or most other) sites, you have IMPLICIT permission to connect because the pages are open and when your browser connects to the web server and asks for a page, the server replies OK. This is the same as my wireless card asking a router for an IP address and connection and it saying OK.
Now, sometimes people don't want you to connect to their webpages - eg they may have a pay for service that you haven't paid for, In this case, they secure those pages, requiring you to have a password/certificate/whatever. This is the same as my wireless card asking a router for permission to connect and the router saying no, you haven't got the correct MAC/password/etc.
So if you believe connectiong to an unsecured wireless router is an offence without the owners explicit permission, I'm afraid you can't browse any more websites until you've asked their owners explicitly.
The rest of us, who have some understanding of technology will of course still be able to browse happily away. Maybe the comments on this site will be a little more sensible then.
It's simple -
1) an UNSECURED router is an open invite to connect. the owner has given permission to connect by not blocking you. If they are too stupid to understand they should be blocking people, TOUGH, they should take some personal responsibility and learn about the technology they are using (you remember personal responsibility, the thing we used to have before it became fashionable to blame someone else for everything that happens to us)
2) Cracking a SECURED connection is an offence.
IT? icon because clearly, some people on here haven't a clue about IT issues