In some devices the NFC transceiver is part of the battery, assuming it has it's own CPU and firmware it could be easily exploited to be trackable from relative

In some devices the NFC transceiver is part of the battery, assuming it has it's own CPU and firmware it could be easily exploited to be trackable from relatively large distances. Other "near field" devices have, such as payment cards and passpoets, have been successfulyy communicated with or exploited using directional antennas from further away than you might think.