 Big issue with doing this digital contact tracing is that you need to be able to protect people's data privacy and their anonymity, which is a trickier thing. In South Korea and Singapore, they were able to do this because they have different cultural social and political norms around it. But in the U.S., for example, that's the big discussion now is how to do this in a way that doesn't violate people's privacy and also protects their personal data.