Location-aware technology and its applications are fundamental to ubiquitous computing. Essential to this technology is object localization and identification. RFID (Radio Frequency IDentification) technology has been shown to be very effective for identification and tracking applications in industry, transport, agriculture and healthcare. However it can also be used for accurate object localization. Indeed RFID technology is ideally suited for such applications, and more generally for context-aware computing, because of the low cost, low power, light weight and endurance of RFID tags. In this paper, the authors study the security issues of RFID localization.