Earlier quoted context omitted.
Did you watch the video? That is not what they did. What you're describing is a brief anecdote they shared about what they were seeing on the ground. Their statistics are based on state level aggregates for New York and California.
State level data is collected using the exact same methods. In many places people with symptoms are told to self isolate until they have difficulty breathing etc. This makes state level data a highly biased sample. There are a few population studies for very specific areas, but no widespread statewide sampling anywhere. PS: The US has ~50,000 Coronavirus deaths. Assuming a very optimistic mortality rate of 0.5% sugge…
This could mean that substantially more Americans have it. (Though on current projections, less than a factor of 2.)