The latest automatic number-plate recognition systems can be used for the detection of average speeds and raise concerns over loss of privacy and the potential for governments to establish mass surveillance of vehicle movements and therefore by association also the movement of the vehicle's owner. Vehicles owners are often required by law to identify the driver of the vehicle and a case was taken to the European Court of Human Rights which found that human rights were not being breached. Some groups, such as the American Civil Liberties Union in the US, claim that "the common use of speed traps as a revenue source also undercuts the legitimacy of safety efforts."