The most common question we get is whether it's legal to use someone else's network without their express consent. Legally speaking, the person who leaves their network open to others may be in violation of their ISP service contract -- many expressly forbid sharing the line with multiple users or computers. It remains to be seen if this is an actual crime, however. It's definitely a violation of some agreements and, if detected, could result in the service being shut off.

It's also technically illegal to connect to a network that you are not authorized to access, in most jurisdictions. In many places, it is a felony, and may have associated mandatory jail sentences and fines. However, there still hasn't been a court case where a network owner has charged another party with theft of services just for connecting to an access point. Without one, there's no precedent for busting small-time wardrivers, warchalkers, and rogue users of open Wi-Fi networks. Hacking into other computers on the Wi-Fi network, or sniffing packets flying by, on the other hand, will definitely get you in trouble.

To keep strictly legal, use NetStumbler or MacStumbler to find true public Wi-Fi sites like NewburyOpen.net or paid services like T-Mobile Hotspot, and only connect to those. (NetStumbler and MacStumbler themselves do not associate with the networks they find. They only sniff them out.) The Michigan Wireless site also has a great article on keeping legal while wardriving here.

Secure Roaming

If you're not using a VPN, be aware that when you connect to an open wireless network, your network packets are traveling unencrypted through a common channel. That means a moderately skilled hacker could capture your passwords and email as they go through the air (Web sites that prompt for credit card info usually encrypt that data automatically). At one conference we attended, a security expert began his presentation by putting up a slide of more than 100 passwords belonging to people in the room who had been using the auditorium's Wi-Fi network. It was that easy.

Of course, thieves could steal your locked rental car from the hotel parking lot, and a crazed business competitor could monitor your cell phone calls, but that doesn't keep you from leaving the house. Wi-Fi security is a matter of personal risk management. Are you worried that someone has a reason to be reading your email? Are you sending confidential information over the line? Get a VPN. For most road warriors, though, being able to get online by any means available isn't a risk, it's a win.

Media Mania

As we've shown, the only real concern you should have when using Wi-Fi in the wild is to use a VPN or encryption for highly confidential data. But you've probably seen or read news stories on the dangerous threat posed by wardrivers, warchalkers, or warspammers -- a threat which is way overblown. Frankly, the whole media response to warchalking and wardriving boggles us. Instead of grasping Wi-Fi's potential, reporters prefer to push the panic button, just as they did when the World Wide Web first appeared. Gasp -- these networks mean anyone might be able to get on the Internet anywhere!

We're working on it.