Just read an article in NETWORKWORLD about how the signals your Wi-Fi system gives off can be used for surveillance to see through walls.  The article, “Stealthy WiFi Spy Sees You Through Walls Thanks to Your Wireless Router,” talks about how researchers in London have created a system that USES Wi-Fi to identify a person’s movements inside a building.

The system gives off no radio waves so it cannot be detected.  It uses Wi-Fi signals to find you and it has been tested and found to be successful through a 1 foot think wall.  There are other wireless networks that “see” through walls to detect and monitor breathing patterns helping to lower the costs of monitoring patients breathing.

Every day we venture into new frontiers.   What was science fiction yesterday is reality today.  Enjoy and beware.