why is securing my wireless network a good idea?

Securing your wireless network is important for a number of reasons. For one thing, it helps prevent theft of service. This is where someone in your neighborhood camps on your wireless network to get Internet access. Though this may seem harmless, having an uninvited guest can slow down the link. If the guest starts Peer File sharing, and illegally downloading and uploading Mp3's, child porn, or sending spam, this activity can be traced to your IP connection, setting you up for future legal trouble with your ISP and law enforcement.

If your wireless network is unencrypted, an eavesdropper can start probing your wireless network, run listening devices (called a sniffer) and capture and analyze all information coming and going to your PC. More brazen hackers in your neighborhood will try to access your PC and access any file shares (such as the Shared document folder) and literally eavesdrop on your lives.

Most consumer grade routers offer WEP and WPA encryption. By far, the most secure setup is to use WPA (or WPA2) encryption, and a passkey that's at least 21 digits. Password protecting your Windows logon account is a good idea, and it should be used in tandem with wireless security.