The UK is doing this now: https://www.reuters.com/article/us-china-health-britain/uk-conducts-random-coronavirus-testing-as-part-of-early-warning-plan-idUSKCN20

The UK is doing this now: https://www.reuters.com/article/us-china-health-britain/uk-conducts-random-coronavirus-testing-as-part-of-early-warning-plan-idUSKCN20K1G1 https://www.reuters.com/article/us-china-health-britain/uk-c... Not quite random since they are only testing people with cold and flu symptoms but these are spread around the country in order to act as an early warning system for spread of the virus.