As beneficial as wearable computers can be, like many things they have some disadvantages. Like many technical devices, they can prove to be quite expensive making it difficult for some people to enjoy. With the perk of being able to wear your device, can also come the nuisance of having to wear equipment that may be heavy or uncomfortable. When out in the heat, your IT could cause irritation which could be very unpleasant. It may also contain a lot of wiring which could get in the way. A big concern that could come from these wearable devices is the privacy risk. As a tool intended to be personalized and private, it could be quite detrimental if it were to be lost or stolen. In organizations where these devices contain private information, having them be lost or stolen could negatively affect the company’s productivity or competitive advantage. Competing firms could find ways to acquire such devices in order to copy or steal valuable information. The access to private information could turn into a complete nightmare and overshadow the advantages of these devices.
http://306is.blogspot.com/2007/04/disadvantages-of-wearable-computing.html
http://www.media.mit.edu/wearables/mithril/intro/topic2.html