What are the risks of connecting to a public wireless network?
Public wireless networks are convenient, but if they are not properly secured, connecting to one might be risky. Whenever possible, only connect to wireless networks that require a network security key or have some other form of security, such as a certificate. The information sent over such networks is encrypted, which can help protect your computer from unauthorized access. In the list of available wireless networks, each network is labeled as either security-enabled or unsecured. If you do connect to a network that is not secure, be aware that someone with the right tools can see everything that you do, including the Web sites you visit, the documents you work on, and the user names and passwords you use. You should not work on documents or visit Web sites that contain personal information, such as your bank records, while you are connected to that network.
Note: This information provided by Microsoft.