It's now a major challenge in the development of wireless network ans yes, I am talking about security. May be the industry is not paying much attention as they are paying for cost effectiveness and energy efficiency, but we cannot deny its affect.I found a good explanatory article about it on IEEE computer society magazine:
Denial-of-Service in Wireless Sensor Networks: Attacks and Defenses
If the network follows cluster head based routing protocol, then it will be sufficient to break the network simply by breaking the cluster heads by broadcasting jamming signals with same frequency but with more power.The opponent can find the cluster heads by determining the Voronoi Diagram of the network node topology and then make any possible attack on those nodes. But if the nodes can identify which packets are sent from its own network and which are not , then the opponent might disable the nodes, but not make them receive wrong information ans the nodes will not respond to the malicious packets.