There is the possibilty that such preliminary steps have been taken to trigger explosions on a number of areas throughout the US.
If a terrorist was making a map that could be purchased at the local store he was more likely making a map of targets where some work was already done.
What if we have specialized cells which do separate things. One group might only do electronics, while another does the explosives. A master map would be needed to pass along.
Such a device suggests to me that we are being set up for an attack at a time of the terrorists chosing.
VRWC_minion,
Speaking of plans. Shortly after 9/11 there was a media report about a person who was captured here in Philly with posession of bluprints of the entire subway rail system. The story seemingly disappeared after that though....hmmm.
These particular tracks are used for Amtrack and our Regional Rail lines that connects the suburbs to the city. My alma mater, Drexel University, is only a few blocks away from 30th Street Station.
"Such a device suggests to me that we are being set up for an attack at a time of the terrorists chosing."
No surprise there.
This is the conclusion I was coming to.
If it was an infrared device it has to be actively transmitting the signal to work. The receiver would consume energy to if it is being used in a manner like a garage door safety switch.
That said, if these are trigger devices, they cannot sit there indefinitely they would run out of battery.