When you are using public wireless networks, your computer is vulnerable to hackers. If you have the latest anti-virus software, that will help protect you. But you may still be vulnerable to individual hackers who may be sniffing the traffic that goes over the network. Some unscrupulous hackers even make a wi-fi signal available so that people will connect to it and they can then sniff all of the traffic that goes through the network.

The best way to use public wireless networks safely is to use something like Hotspot Shield to protect yourself and your computer. When you use this, it creates a VPN (virtual private network) connection between yourself and a proxy so that all of the traffic you sent is completely encrypted which makes it unreadable.

This is a free service, and it works on both Macs and PCs. If you are going to use public wireless networks, you should be using a service like this to protect yourself.