“but there are so many unsecured (no password) home networks out there....”
I have one right here.
Last week while on my back deck listening to tunes on my laptop i realized that an un-secured network somewhere had a higher power reception than my own wireless router so i used their internet instead of mine for the day.
Worked great.
I don't doubt it. But you may have been compromised already, and if not you will be eventually.
An unsecured wireless is an obvious invitation to others. Well guess what? When you connect to such a network, you are a "peer" (on the same local net) to any other wireless user on that access point.
Including, of course, the guy who set it up, who has been waiting for you. Or the guy in the car, war-driving, and looking for victims. Bet on it -- there's a hacker who knows about, or set up, that unsecured wireless.
He is the spider in that web. As soon as you connect, he can connect to your computer. Unless you have strong passwords on your login accounts, he will be able to access your hard drive (e.g. on Windows using the default C$ share) with "administrator" privilege.
Connecting to an unsecured wireless is like having unprotected sex daily with strangers. Sooner or later you WILL get infected, or have your identity stolen, or your credentials copied.
It's a free country -- do as you wish. But at least, please use strong passwords, and a strong firewall that actively warns you of attempts to connect to your computer. That'll mitigate the danger a little.
Unsecured users are EXTREMELY common.
Years ago I got my hand on a Linksys wireless card. I didn’t have a service or a provider, so it sat on the shelf for a while.
Well, one day I plugged it in just to see and the darn thing connected!!
My neighbor had wireless with no security turned on.
So a couple months later. I charged the laptop battery good, set it on my front seat in my car, and just for the hell of it, started Network Stumbler and drove aroung the block.
I was hitting two to four wireless networks per block. Half or so of them unsecured.
The reason is people, probably most people, don’t want to be network engineers, they just want it to work out of the box. So they get the hardware, plug it in and turn it on, then do the minimal amount they need to get connected.
Part of the problem also being the people who run unsecured networks are also the people who never turned off sharing for their files and folders. Odds are very, very high that they’re infected.