>>9784323 (PB)
The tag depicted is NOT an RFID tag. It does NOT store a serial number at all and as such is unsuitable for tracking.
Instead, the depicted tag is an LC circuit theft / EAS tag. It's essentially a capacitor with an antenna. An RF field is applied at a specific frequency, and if the capacitor is intact, the RF field will detune, which is then sensed by the detection circuit to trigger an alarm. Mechanically destroying the capacitor in the tag will disable the tag.
See also https://en.wikipedia.org/wiki/Electronic_article_surveillance