An RF tag has an enable/disable circuit connected to a critical part of an electronic object/circuit, e.g. a computer mother board. The critical part of the circuit is any circuit component and/or connection that can enable and/or disable the electric circuit operation. Signals are sent to the tag to...http://www.google.de/patents/US5874902?utm_source=gb-gplus-sharePatent US5874902 - Radio frequency identification transponder with electronic circuit enabling/disabling capability
