In wireless network is deployed to monitor certain events and pinpoint their location, the location information is intended only for legitimate users. However, an eavesdropper can monitor the traffic and deduce the approximate location of monitored objects in certain situations. The authors first describe a successful attack against the flooding-based phantom routing, proposed in the seminal work by the researchers. Then, they propose random-walk, a two-way random walk, i.e., from both source and sink, to reduce the chance an eavesdropper can collect the location information. They improve the delivery rate by using local broadcasting and greedy forwarding.