February 08, 2004

How to steal books from the library

Lately I've been using the Palo Alto library some more (I go through spells of heavy use until my pathological late book returning racks up some major fines and then I avoid the library till I feel ready to pay up). Anyway, the library has a checkout system which is integrated with their anti-theft system in an interesting way: Each book has what appears to be the standard anti-theft gizmo that is detected by those doorway pillars. A lot of these systems deactivate the in-book tag by applying a large magnetic field but in this system the anti-theft gizmo is apparently in the pocket where the "due date" cards go. As long as there is a due date card, the alarm doesn't go off. I don't know physically exactly how the system works but it looks like the cards themselves are somehow metallic.

Anyway, even without knowing exactly how it works, this system has two useful properties:

  1. The cards aren't tied to any particular book.
  2. You can carry a card into the library without setting off the alarm.

Pretty clearly, this allows you to steal a more or less unlimited number of books without triggering the system. Go to the library and take out a couple of books. Then take the tags into the library, put them into the books you want to steal and walk out. Repeat as desired. Not that I'd ever do this of course, but as a security guy, my instinct is to pretty much automatically try to figure out how to bypass any security system. Posted by ekr at February 8, 2004 06:03 PM | TrackBack


Students used a more lo-tech attack when I was an undergrad: they'd simply throw books out the window, walk around the building and pick them up :-)

Posted by: nagendra modadugu at February 9, 2004 09:52 AM

Metaphysics is the finding of bad reasons for what we believe upon instinct, but to find these reasons is no less an instinct.

Posted by: penis enlargement at September 19, 2004 10:44 AM
Post a comment

Remember personal info?