It's not hacking. The majority of the story is about the fact that people don't think to password-protect their networks. This is because people are stupid/too lazy to secure their routers. No story.
I don't believe that a quarter of home wireless networks have no password. I work all over the place and used to regularly scout around for open wireless networks just to see if they were there. 5 years ago I often found them. Today it's much rarer, IMHO around 5 percent. Generally routers come out of the box with encryption enabled, and the Windows wizards that the majority of people will use to set up their new hardware turns encryption on right at the start. It has been my experience that you often have to work quite hard to make a network open.
Fair point about public access points though. It's worth remembering that they may not be secure before using your internet banking in Starbucks - though I would like to see what kinds of usernames and passwords they were able to harvest. Retrobike, maybe?