bar code reader 110 may be any bar code reader including an optical bar code scanner which uses laser beams to read bar codes bar code reader 110 may be located within a checkout counter mounted on top of a checkout counter or incorporated within a hand held device as shown in fig5 the prior art deters theft by combining systems 100 and 200 with placing a security tag 500 on the product packaging in addition to the bar code the security tag 500 consists of a resonating circuit 540 having a resistor 530 capacitor 520 and fuse 510 connected together in electrical series in operation the circuit 540 is designed to resonate at a particular electromagnetic frequency for example in the 1 to 1 2 ghz range if a strong enough electromagnetic wave 550 impinges on the circuit the circuit will excite and generate enough current to blow the fuse 510 thereby disabling the electrical circuit 540 and deactivating the security tag device 500 the electromagnetic wave 550 is emitted by a deactivation device 560 that incorporates rf circuitry to produce a frequency and generate sufficient power to emit the electromagnetic wave 550 through an antenna it should be appreciated by those skilled in the art that the electrical circuit.