"Two NIJ-supported studies with very different results show that GPS technology may be used to help prevent crime in various ways. Using sophisticated technology to control crime generally appeals to both the public and policymakers because it prompts visions of reduced crime and improved safety. GPS technology can track an offender's movements in real time and is designed to reduce crime by enhancing the likelihood that law enforcement will detect criminal behavior. For the public, this conveys the notion of a virtual prison, in which offenders are prohibited from engaging in any wrongdoing. Critics, on the other hand, maintain that the idea of pervasive and constant surveillance offers a false sense of security and does little to actually prevent crime; they often point to horrific crimes that have occurred while offenders were under GPS supervision."