Wireless networking is inherently insecure. From jamming to eavesdropping, from man-in-the middle to spoofing, there are a variety of attack methods that can be used against the users of wireless networks. Modern wireless data networks use a variety of cryptographic techniques such as encryption and authentication to provide barriers to such infiltrations. However, much of the commonly used security precautions are woefully inadequate. They seem to detract the casual sniffer, but are unable to stop the powerful adversary. In this article, we look into the technology and the security schemes in IEEE 802.11, cellular and Bluetooth wireless transport protocols. We conclude that the only reliable security measure for such networks is one hat is based on application level security such as using a VPN.