Government Technology Agency staff demonstrate Singapore's new contact-tracing smartphone app called TraceTogether, as a preventive measure against the COVID-19 coronavirus on March 20, 2020. Bill Marczak, an expert in cellphone surveillance technology, told CPJ about the implications for journalists as governments ramp up their capacity to monitor citizens in a time of crisis. (AFP/Catherine Lai)
Government Technology Agency staff demonstrate Singapore's new contact-tracing smartphone app called TraceTogether, as a preventive measure against the COVID-19 coronavirus on March 20, 2020. Bill Marczak, an expert in cellphone surveillance technology, told CPJ about the implications for journalists as governments ramp up their capacity to monitor citizens in a time of crisis. (AFP/Catherine Lai)

Expert Bill Marczak: What journalists should know about coronavirus cellphone tracking