Lack of bandwidth
CIOs trying to extend core applications to handheld devices soon discover that wireless data networks are many times slower than conventional 56K dial-up connections; 802.11 wireless LAN innovators using fat-client devices are learning the same thing.
Just like cell phones, there are dead spots where devices can’t connect. Furthermore, connections can be dropped without warning. No one is going to risk a purchase or stock trade when there is no guarantee it will go through.
A hacker can decrypt most wireless data transmissions in a New York minute using software readily available on the Internet. For this reason, Pentagon CIO John P. Stenbit recently banned the use of some wireless devices in military buildings.