Hmmm... mobile phones.... unlikely. A hack like that conceivably may work for pabx's (you might be able to steal an outside line from a pabx, and certainly older telco exchanges  with certain codes/frequencies) - which is the likely source of this, if you like, rumor.
 
check out this link
 
chainletters.org/hoaxes.shtml
 
Robert Spykerman
----- Original Message -----
From: [log in to unmask] href="mailto:[log in to unmask]">Andrew Curphey
To: [log in to unmask] href="mailto:[log in to unmask]">[log in to unmask]
Sent: Tuesday, October 30, 2001 7:03 PM
Subject: FW: Mobile Phone users - WARNING From Roy Bloor

For those who may not have seen this I hope it is of use. Not in related to the list directly, I know, but I am sure of relavence to many.
 
Sent: Saturday, October 27, 2001 2:20 PM
Subject: Mobile Phone users - WARNING

Subject: FW: [Fwd: [Fwd: FW: MOBILE PHONE USERS - MOBILE PHONE MESSAGES RECEIVED  FROM BT:

If you get a phone call on your mobile from an EIRCELL or a DIGIFONE engineer telling you that they are doing a check on your phone and that you should press #90 or 09# END THE CALL IMMEDIATELY. 
 
There is a fraud company on the go who have devised a device that once you press #90 or 09# they can access your SIM Card and make calls at your expense.

Tell as many people as you know who have mobile phones so this can be put to
 an end.

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