Fun_People Archive
30 Dec
Mobile phones used as trackers 

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From: Peter Langston <psl>
Date: Tue, 30 Dec 97 12:28:12 -0800
To: Fun_People
Precedence: bulk
Subject: Mobile phones used as trackers 

Forwarded-by: Nev Dull <nev@bostic.com>
From: David M Walker <davidw@datamgmt.com>

The following article appeared on 29th December 1997 in the Times
(http://www.sunday-times.co.uk). I am the Technical Architect for
the Swisscom Mobile project and comment below ...

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
		Mobile phones used as trackers
	        BY MICHAEL EVANS AND NIGEL HAWKES

  MOBILE PHONES can be used as tracking devices to pinpoint users within a
  few hundred yards, according to a report yesterday.

  Sonntags Zeitung, published in Zurich, said Swiss police had been secretly
  tracking mobile phone users through a telephone company computer.

  "Swisscom [the state-owned telephone company] has stored data on the
  movements of more than a million mobile phone users and can call up the
  location of all its mobile subscribers down to a few hundred metres and
  going back at least half a year," the paper reports, adding:  "When it
  has to, it can exactly reconstruct, down to the minute, who met whom,
  where and for how long for a confidential tte--tte."

  Swisscom officials confirmed the practice but said information about
  mobile phone customers was handed over only on production of a court
  order. The newspaper claimed that about 3,000 base stations in Switzerland
  tracked the location of mobile phones as soon as they were switched on.

  Renato Walti, an investigating magistrate in Zurich who specialises in
  organised crime, told the paper: "This is a very efficient investigation
  tool."

  Toni Stadelmann, head of Swisscom's mobile phone division, is quoted as
  saying: "We release the movement profile of mobile telephone customers on
  a judge's order."

  In Britain, six mobile phone companies are understood to have arrangements
  with law enforcement agencies to provide coding information on individual
  phones used by suspected terrorists or serious criminals, but there are
  legal and procedural restrictions. As in all intelligence and police work,
  according to one intelligence source, technical surveillance is carried
  out only for what the source described as "focused" operations on key
  individuals.

  "Some people might think the law enforcement authorities are tracking
  every mobile phone user, but that is complete nonsense. We have to have
  our antennae out to get the critical leads, but once we've got a lead we
  focus on that individual and a lot of effort goes into filtering out
  extraneous information."

  Earlier this year there was a row in Australia when police admitted that
  they were using the mobile phone network to keep track of known criminals.
  Signals emitted by the criminals' phones and picked up by local base
  stations were being used to pinpoint people, providing "a very valuable
  investigative tool", according to Sergeant Frank Helsen of the New South
  Wales Police Service Crime Data Centre.

  The method worked even if the phones were not in use, since they emit
  signals automatically every half hour. Data collected by the phone
  companies whose base stations pick up these calls was being reconstructed
  to pinpoint the whereabouts of the phone users.

  Chris Puplick, the chairman of the New South Wales Council for Civil
  Liberties, protested that walking around with a mobile phone was "like
  walking around with a beeper or an implanted transmitter".

  In the Australian case, the mobile phone companies said that they did not
  routinely keep the data from phones but would do so if a warrant were
  issued in advance. The police service declined to say how often this
  happened.

  In the Swiss case, it appears that the data is automatically recorded.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
It is true that while a call is in progress the person can be tracked with
standard radio tracking techniques. It is also true that Phone Companies
store the Call Data Record (CDR) for billing and marketing purposes. Most
Telcos now try to store 18 months of this data (Swisscom will be about 2Tb
of info after 18 months). The CDR contains the base station or cell that
was being used (remember that a user in a car is likely to pass through many
cells. Cells overlap depending on location and may be small (a square
kilometer in a town) or large (fifty square kilometers in open flat
countryside).

But the statement:

 "Swisscom [the state-owned telephone company] has stored data on the
 movements of more than a million mobile phone users and can call up the
 location of all its mobile subscribers down to a few hundred metres and
 going back at least half a year," the paper reports, adding:  "When it
 has to, it can exactly reconstruct, down to the minute, who met whom,
 where and for how long for a confidential tte--tte."

is totally implausable, we have enough problems with the volume of CDR data
as it is without storing the radio direction info as well.

It is well known that subscribers may also not  be the user, e.g.  a man
may be a subscriber twice, but may give one phone to his wife - so who is
using the phone and how do you know that ?

Furthermore Swisscom have a service called 'Natel Easy-Go' where you can
pay cash for a pre-paid mobile phone. Unless the person pays by credit card
to re-charge the prepayment element you don't even know who the subscriber
is !

Finally the Police in most countries do use the CDR information from Telcos
both mobile and fixed line, and in most countries it is controlled by court
order. Even the limited information that I have described as being available
helps catch criminals, who like all of us are creatures of habit and
normally just pick up the nearest phone !

davidw
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