South Korea has been largely able to track people who had been in close proximity to those who are diagnosed with Wuhan Corona Virus by mostly two means :

  1. Credit Card Usage
  2. CCTV Close Circuit Television

South Korean law allows the Minister of Health and Welfare to request telecommunication companies through the police to reveal location of cell phone signals, for precaution of infectious disease . and under the same law, can retrieve Credit Card and Transportation Card usage and CCTV recordings . and then can pass-on this information to regional administrative offices, who then notify effected establishments where those effected people had been to . thus whole buildings, department stores and huge super-marts have been notified immediately for them to close and disinfect for the rest of the day or more . but this is not possible any more because :

  1. a religious sect.has been found to be source of mass-infection, whose practice is dubious that its followers refuse to be identified, not-to-mention their recent where-abouts,
  2. whole numbers of those who came in contact with possibly infected are now too many and that needs unrealistic man-power .


– Hey, What are you doing Now ? Korea Tech BLog