How do you distinguish this case from the obligation to sign tax returns? (I think that is 26 U.S. Code § 6061, https://www.law.cornell.edu/uscode/text/26/6061)

The talk a bit about it here, https://www.irs.gov/Tax-Professionals/The-Truth-About-Frivol...

And this is kind of similar but about the 5th Amendment. http://openjurist.org/775/f2d/1292/eh-mosher-v-internal-reve...