Each year, the Internal Revenue Service deals with individuals who refuse to pay their taxes. Some believe the federal income tax is unconstitutional, others simply don’t want to pony up the cash, and a few have done it as a form of protest against non-tax-related policies such as gay-marriage laws or the Vietnam conflict.

In the past, the IRS would slap the “illegal tax protester” label on those individuals. The goal was to flag them for enforcement actions and alert IRS employees to be cautious in dealing with them — some nonpayers are combative or violent.

The IRS stopped using the label after 1998, when the Republican-controlled Congress passed a law prohibiting it for the agency. The argument was that the designation stigmatized the protesters and biased IRS employees against them, even after they paid up.

Various federal courts have rejected the notion that individuals can ignore tax laws. Here’s what the Justice Department’s criminal tax manual says about the matter:

“Over the past thirty years, illegal tax protesters have developed numerous schemes to evade their income taxes and frustrate the Internal Revenue Service under the guise of constitutional and other objections to the tax laws. Individuals who merely express dissatisfaction with the income tax system are not criminally prosecuted. However, the right to freedom of speech is not so absolute as to protect conduct that otherwise violates or incites a violation of the tax laws.”

Below are a few examples of famous tax protests and protesters throughout U.S. history:

Whiskey Rebellion

In 1791, Treasury Secretary Alexander Hamilton proposed the first U.S. tax, an excise on distilled spirits. Hamilton saw the tax as necessary to help pay down the considerable debt the nation incurred from the American Revolution.

During that period, farmers used whiskey for trade, and many of them objected to the tax.

Protests emerged in Appalachia and especially Western Pennsylvania soon after Congress approved the excise in 1791. Over a period of several years, opponents tarred and feathered tax collectors and even burned one of their homes.

President George Washingtion sent about 13,000 troops to stop the rebellion in 1794. In October of that year, he traveled to review the expedition’s progress, marking the first and only time a sitting U.S. president has personally led a military force, according to historian Joseph Ellis and a National Geographic fact sheet.

Julia “Butterfly” Hill

Hill first made a name for herself by living in a California redwood for 738 days, between 1997 and 1999, in an effort to prevent a logging company from cutting down the tree.

In 2003, Hill refused to pay her taxes as a form of protest against the war in Iraq. She instead sent the money she owed to nonprofit environmental and social-service organizations.

Hill was still fighting the IRS as late as 2011, according to a letter she posted on the National War Tax Resistance Coordinating Committee’s Web site. “It is not easy, but it is absolutely one of the most empowering actions I have ever taken, and continue to take,” she said.

Gordon Kahl

Kahl was a decorated World War II veteran who stopped paying his income taxes in 1967, saying in a letter to the IRS that he would not support a government influenced by Communism and Satan.

The government charged Kahl in 1976 with intentional failure to file tax returns for two years, for which he ended up serving eight months in prison. He continued refusing to pay income taxes after his release.

In 1983, Kahl killed two U.S. marshals in North Dakota during a shootout as officials tried  to arrest him for violating parole. Authorities tracked him to Arkansas, where he and a county sheriff were killed in another shootout.

Charles Merrill

Merrill, a gay artist, stopped filing his federal income taxes in 2004, after President George W. Bush called for an amendment that would define marriage as a union between a man and a woman during his State of the Union address that year.