Security Tags.
Security tags are devices that are attached to products to prevent shoplifting and are often used in conjunction with an Electronic article surveillance system. SelectaDNA or Smartwater are such security tags - a forensic fluid which contains millions of tiny fragments which have a unique number called "SIN" ("SelectaDNA identification number"), and registered in a national police database together with the owner's details, is etched into each of those particles.
Anti-theft system
"DBflex" by Philipp Cachée - Philipp Cachée. Licensed under Attribution via Commons - https://commons.wikimedia.org/wiki/File:DBflex.JPG#/media/File:DBflex.JPG
"DBflex" by Philipp Cachée - Philipp Cachée. Licensed under Attribution via Commons - https://commons.wikimedia.org/wiki/File:DBflex.JPG#/media/File:DBflex.JPG