Even I find this one hard to believe.
Doing some early morning research today I discovered that the Internal Revenue Service has an entire publication devoted to the topic Why do I have to Pay Taxes? (peculiar capitalization in the original).
Hm. I had supposed that I pay taxes to fund IRS expense in producing booklets, now that I think of it.
To save my loyal readers the trouble of actually reviewing this document, I will tell you that it is only two pages long, and unlike every other IRS pub I have ever used, it is written largely in purple and lavender script. Also, I will tell you (with hyperlinks, unlike the pamphlet, which doesn't bother to quote the actual wording of the cites) that the authority to levy (federal income) taxes lies in article I, section 8 of the U.S. Constitution, supplemented by the Sixteenth Amendment, and implemented by Title 26 of the U.S. Code.
It's hard for me to believe that a pamphlet printed in purple would sway tax protesters, its apparent intended audience.