Imagine how devastating a pandemic would be without the Center for Disease Control to monitor and mitigate illness outbreaks.
They should have that information on record and may be asking for it merely to report on dividends and interest paid to its customers.
Your content earnings will be added to your other income — wages, dividends, interest, rental, etc — to come up with total earnings figure which may be subject to tax at 20%, 40% or 45%.