The government of Singapore is tracing the coronavirus in ways that are simultaneously impressive and terrifying for those who worry about high-tech dictatorship.

The latest example: On Saturday, a friend living there received a WhatsApp message from the Singaporean government with instructions to download a new coronavirus tracing app called "TraceTogether."

The app uses Bluetooth to help the government track down and notify people who have come into close contact with somebody infected with the coronavirus.

How it works, per ChannelNewsAsia (CNA):

Singaporeans download TraceTogether from the App Store, enter their cellphone number and consent to their numbers being "stored in a secure registry."

They switch on Bluetooth and push notifications. According to the Singaporean government, the app attaches a random ID to your cell number.

"It then uses Bluetooth to detect other users who come within two to five meters of you and records their random IDs internally," per CNA.

If a user of the app tests positive for the coronavirus, Singapore's Ministry of Health will have them send their app logs to the government.

The Singaporean government will then "decrypt the random IDs to determine the mobile numbers of my close contacts." This means that Singaporeans won't have to rely on their memories to recall whether they've had contact with somebody who later tests positive for the virus.

Between the lines: This app is a high-tech form of contact tracing — identify an infected person, then immediately identify who they might have infected, test those people, on down the line.

Testing is the first and essential step to making it work. That's why we can't do it. Testing plus contact tracing is the right thing to do in any outbreak, it's what worked in Singapore and South Korea.

There are ways to do it that are not incompatible with freedom but we can't do it here in the United States because testing sucks so much here.

The other side: Some of the government's techniques would be difficult to implement in a free society. Over many decades, Singaporeans have become comfortable unquestioningly following directives from their dictatorial government.