Mostly. But I've known a few libs who took things to an extreme, and heard about many more. Including one gent who worked for Unisys and actually sued them to force them to stop using the SSN he renounced, and then to stop withholding his pay. I believe he was successful all around; I haven't heard of him being carted off to jail, and I'm on the periphery of some of the same circles he is, so I think I would have heard about it.
Five years ago at least, the thinking was that while US citizens are required to pay taxes, the official definition of "US citizen" includes only the federally-controlled zones such as US Virgin Islands. People in the states were actually state citizens not US citizens, and therefore under the letter of the law they are not required to file. Some have also played with the legal definitions of "income", "wages" etc.
Their thinking also included the concept that the people at the top have known this all along, and that to correct this "situation" would require the closing of some rather large constitutional loopholes. The IRS itself refers to the system as one of "voluntary compliance" which they have taken to believe has serious legal implications in their favor.
The biggest flaw in all this is that judges don't act within the letter of the law. It's not enough to whip out your Black's and explain that the official legal definition of "citizen" is something different than what 99.9999% of the population believes, and that the entire system depends upon. The judge can rule however s/he likes. It's not like a logical/rational system where if you find the flaw you topple the entire hypothesis. There are arguments for and arguments against, and most judges will act politically, follow precedence, etc.
Check out
this dude who believes that the mere fact they haven't gotten him for 10 years means that he must be onto something.