Daily Mail has collected some of the fans' posts on social media and also retells the story. Shortly before the tribute concert, the Irish singer had protested against the Catholic Church by tearing up a picture of Pope John Paul in American TV.
"Fight against the real enemy" said Sinéad O'Connor, who had been upset after reports in the media about sexual abuse within the church.
The reactions were strong and at the tribute gala in New York, she was booed by the audience. This was after Kristofferson had first introduced her as an artist synonymous with integrity and courage. In 2010, Kristofferson told that the organizers had asked him to go out and lead Sinéad O'Connor off the stage. Instead, he went forward, put his arm around her shoulders, and said "Don't let those bastards get you down".
Sinéad O'Connor responded by singing Bob Marley's "War".
Kris Kristofferson eventually dedicated a song to her, "Sister Sinead".
Sinéad O'Connor died, 56 years old, last year.
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