The 16th Amendment states, " The Congress shall have the power to lay and collect taxes on incomes, from whatever source derived without apportionment among the several states, and without regard to any census of enumeration."
In recent history the IRS targeted the entertainment industry for large scale tax changes. Specifically in the definitions of employee vs. independent contractor and the determination thereof. These changes were made by broadly interpreting existing tax laws and unfortunately came at the expense of small companies without the resources to fight the large levies placed on them by IRS and state agencies.
The recent insurgence of patriot groups, militia and other similar groups is related to the rising discontent with the tax system as well as the federal government. These groups, in general, feel the government has become too powerful an entity in which the rights of the individual are continually eroded. Recent disclosures, such as the government's radiation experiments upon unwitting participants, the Iran-Contra drugs-for-weapons scandal, the leaving behind of American POW's in North Korea, or the CIA's fundraising by selling crack in our inner cities, has led to an ever increasing distrust of the American Government. And now, recent evidence has suggested that the sixteenth amendment to the Constitution, upon which all authority for modern taxation rests, was never legally ratified. The number of states that ratified it was less than the three-fourths margin needed to declare it an amendment, yet the acting Secretary of State in 1913 declared it ratified. Patriot groups have used this information, as well as an extensive knowledge of the laws, U.S. codes, and the Constitution, to "legally" avoid paying taxes.
Multiple members of congress have made it their platform and vow to change the tax system and the IRS. One publication suggested that in the next year some 20 million citizens will have an adverse encounter with the IRS.