Spread-spectrum net (vulnerability of)

[Robert J Woodhead <trebor@foretune.co.jp>]

You can put up such a network, but given that your boxes have to receive
the signal, it will be detectable (but not understandable) to 3rd parties.

Anyone who wants to take you down will only need (1) a detector that can
point out your boxes and (2) a small caliber rifle.

Since the cost to find and destroy is much less than the cost to make and
deploy, a covert network of this sort wouldn't last long.  An _overt_
network, perhaps a commercial entity that networks an entire city, would
be an interesting prospect.

The techniques for maintaining location information on actual machines
connected to the net, and for updating them as they move, are actually
quite simple and well understood (cellular telephones are a simple,
dumb version of the technology).  The trick is to find out a way that
the network can know where you are but not give that information out
(even to the owners of the network), without unacceptable overheads.