I think that the >70% number is misleading. It's 70% of cases for which we have data where the transmission happened. For a good majority of cases the transmiss

I think that the >70% number is misleading. It's 70% of cases for which we have data where the transmission happened. For a good majority of cases the transmission happened at an unknown place. It's just that for those where it is known, most are happening at home (as opposed to e.g. at work). Those unknown transmissions are what you want to attack with a mass testing regime. That seems entirely doable, given cheap and simple testing at home.