What if there were 10,000 cryptocurrencies, not worthless, but worth maybe  $0.00001 each.
And every taxpayer owned one or two.

IRS Form 1040 asks if at any time during the year you received, sold, exchanged, or otherwise disposed of any financial interest in any virtual currency.

Imagine if everyone reported holding a cryptocurrency on their tax form, but most of them by far were worth nothing.