Shirley Allen was a former nurse whose family's 1997 attempt to get her involuntarily committed led to a 39-day standoff (described by some as a "siege") with Illinois State Police and other law-enforcement agencies.

Her husband died in 1989.

On September 22, 1997, officers of the Christian County, Illinois sheriff's department attempted to serve commitment papers that had been obtained by a court order after a petition by some of her relatives. Though the relatives have said they were concerned about her mental state, some have alleged that the motive behind their attempt to get her involuntarily committed was to get control of her land; there were two oil wells on her 47-acre farm.

The police were accused by some of using "military-style tactics" against Allen after she allegedly fired a shotgun at officers. (There is some controversy as to whether Allen fired first, and indeed, police have offered contradictory statements on this.) The police used tear gas, rubber bullets, Barry Manilow music played at high volume day and night, and a police dog to attempt to take her into custody, and eventually shut off her power and water, and arrested a neighbor who tried to bring her food and water. Numerous protestors stayed at the site during the standoff or siege including members of the "militia movment."

State Police Director Terry Gainer said at the time that police were "there for this woman's protection and for the protection of her neighbors. I think we're doing the right thing. We can't afford not to."

After six weeks in a mental hospital, Allen was released when doctors said she posed no danger to herself or others.

The standoff led to international controversies over the cost of the operation as well as involuntary commitment laws. So-called "patriot" and militia groups, as well as the Libertarian Party, called for reform of Illinois mental health laws providing for the hospitalization of people who do not break the law.

Dave von Kleist recorded a song about the standoff, "The Ballad of Shirley Allen."