There are three types of theft detections systems I'm aware of. The kind
that requires a sticker and is a resonant circuit is made by a company
called CheckPoint. The sticker has a metal foil resonant circuit tuned to a
specific frequency. The detectors are tuned to a specific frequency, so
little else will set them off. I worked in a library that used the
checkpoint system. We had special due date cards that went in the pockets
to "deactivate" the sticker. The cards themselves had a sheet of foil
embedded inside. You'll see the checkpoint sticker most often in the pocket
of a book. In commercial applications, it may be disguised as a UPC. A tear
in the circuit is usually enough to deactivate it (razor or simply rip some
of the sticker off).

The other major system in use, especially in libraries, is the 3M
Tattletape. These are thin strips about 3-5" long and about 1/8" wide. They
are magnetically deactivated, so a strong magnet will detune them. Of
course, so will pulling out the Tattletape. The most common location for
tattletape is in the spine, so the book can be slid along its spine in the
desensitizer. The tattletape is also used a lot in cd stores.

The third I've only seen in retail. It's a small plastic strip about 1 1/2"
long, 1/2" wide and 1/16" high. It's also magnetically desensitized, based
on the desensitizer's I've seen. Ripping the sticker off seems to be the
only safe approach.

-----Original Message-----
From:   Mroczkowski [SMTP:mroczkow@FLASH.NET]
Sent:   Monday, December 01, 1997 10:08 PM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: anti-theft sticker

<snipsnipsnip>
Gee Whiz - does this mean I could defeat these things by carrying a
small EMF pulse generator, such as an electric butane BBQ starter
wand?  ;-)

CIAO - Martin.

Martin R. Green
mrgreen@NOSPAMbigfoot.com

To reply, remove the NOSPAM from the return address.
Stamp out SPAM everywhere!!!
=================
Actually, they are deactivated by a pulse that "burns them open"...somet
hing
a B-B-Q starter would be hard pressed to produce;^))

Simply covering the patch with a piece of aluminum foil will render it
inoperative.

-Cheers, Hank