It's a hard analogy, calling tax as robbery but it has some valid points, if we suppose that the violence aspect needed to fulfill robbery is the government and the consequences of denying to pay.

Speaking of a tax-free society, how to manage society and all their problems? I read a lot about robbery, theft, rape but not how to do it better. You won't tell me that pure ultra-capitalism would make us a better world.

Shoot the weak?