Oprah? Did no one say Oprah... I've been looking through this thread for a while, but must have missed that one.
My other choice, Madonna, was already mentioned, thus I give you the far less well-known Judi Bari:
Judi Bari was an American environmentalist and labor leader, a feminist, and the principal organizer of Earth First! campaigns against logging in the ancient redwood forests of Northern California in the 1980s and '90. She also organized efforts through Industrial Workers of the World Local 1 to bring timber workers and environmentalists together in common cause.
On May 24, 1990, Bari was severely injured by a pipe bomb which exploded in her car as she and fellow Earth First! member Darryl Cherney traveled through Oakland, California, on their way to Santa Cruz. Bari and Cherney were on an organizing tour for "Redwood Summer," a campaign primarily made up of nonviolent protests focused on saving redwood forests in Northern California. The Oakland police and the Federal Bureau of Investigation (FBI) immediately accused Bari and Cherney of knowingly carrying a bomb for use in an act of terrorism. A year later, Bari and Cherney filed a federal civil rights suit claiming that the FBI and police officers falsely arrested the pair and attempted to frame them as terrorists so as to discredit their political organizing in defense of the redwood forests. It is still not known who placed the bomb in Bari's car.
In 2002, a jury in their federal civil lawsuit exonerated Bari and Cherney by ordering four FBI agents and three Oakland Police officers to pay a total of $4.4 million to Cherney and to Bari's estate for violation of their First Amendment rights to speak and organize and for false arrest and unlawful search and seizure. Judi died in 1997 of breast cancer, five years before her exoneration.
(to learn more, watch the documentary "A Forest for the Trees," it's quite good.)