Q. I currently use an air card over a 3G network. Is this more secure than a wireless connection at the coffee shop? Thanks!
—Larry from Goldendale, WA, listening online via Kim's Club podcast

A. Good question, Larry. This is a timely issue, given the spreading adoption of cellular broadband. As always, the answer is determined by the circumstances.

Properly encrypted home Wi-Fi is very secure. Outside sources can't access your network. And you only share it with people you trust.

Public Wi-Fi is a different story. Anyone using the same Wi-Fi point can potentially access your data. Why? Public hotspots typically are not encrypted. Or, they could use inadequate encryption.

A data thief would use software called a packet sniffer. These programs analyze all traffic going through the router. This is where crooks spend most of their energy. Wi-Fi is everywhere. And it's often easy to steal the information.

Of course, some of that data will be encrypted. E-mail systems encrypt passwords, for instance. But e-mail itself is not encrypted. So, it could be stolen by someone using a sniffer.