An RFID device includes a chip, an antenna operatively coupled to the
chip, and a visual indicator operatively coupled to the chip. The visual
indicator provides a visual indication of an operative state of the
device. The visual indication may be human readable and/or machine
readable, and may provide visual indication that is dependent on a change
in an operative state of the device. The operative state that triggers
the visual indication may include a state in which the chip has
temporarily or permanently been rendered inoperative or disabled, that
is, in which the chip no longer responds to, or otherwise interacts with,
ordinary incoming RF signals such as from a device reader. The visual
indicator may be included in a display that functions by any of a variety
of suitable mechanisms, such as by use of electrochromic materials,
thermochromic materials, liquid crystals, or chemically-reactive
materials.