Posted by now you know, a resident of Another Palo Alto neighborhood, on Jul 9, 2007 at 3:53 am
I thought the community figured out about this years ago...
First of all, the 'ancient' appearance of the doorway security sensors gives a big clue of whether or not they actually function or not. Second, has anyone actually heard them go off before?
Truth is... the security sensors don't work and are just there as decoration (helps deter some thefts). Other libraries use RFID technology which imbeds microchips within the covers of books. Upon checkout the RFID is deactivated so the book can pass through security sensors.
The libraries use cheaper alternatives for security. DVDs as you may notice have yellow sticks to prevent people from just opening cases. Nothing will stop a person from taking the case altogether, but the case itself will have to be smashed to retrieve the disk. Not 100% effective, but deters thefts because having a case/cover for resale is preferable. As for CDs... nothing to prevent thefts. Mitchell Park installed a mirror by the CD section to allow staff members in the cubicles to peek in on customers in the section after there was a rash of stolen CDs a while back. Books... nothing as well, but used books aren't exactly appealing or worth selling.
Every year a branch like Mitchell Park can have hundreds and hundreds of books, DVDs, Cds, etc go missing. The items get classified as 'trace' and some poor soul (a librarian) goes around the library trying to locate the item on the shelves. If we're lucky, the item is there probably because it was misplaced or taken by accident. The library continues to look for 'traces' until they are found or until we simply give up and classify it as 'missing.'