Harry Potter author JK Rowling joined a group of 150 writers and academics who signed a letter denouncing so-called cancel culture.
The letter, signed by bestselling authors Salman Rushdie and Margaret Atwood, condemned “a vogue for public shaming and ostracism” and “a blinding moral certainty”.
"Cancel culture" refers to online condemnation and shaming of people whose views are perceived to have caused offence.
The letter, which appeared in Harper's Magazine, said: "The free exchange of information and ideas, the lifeblood of a liberal society, is daily becoming more constricted."
Russian chess grandmaster Garry Kasparov, American intellectual Noam Chomsky, feminist Gloria Steinem and author Malcolm Gladwell also put their names to the document.
Last month, Rowling became the target of an online campaign for her views on transgender issues. The exchanges led the writer to reveal her history as a victim of an abusive relationship.
“It is now all too common to hear calls for swift and severe retribution in response to perceived transgressions of speech and thought,” the letter said.
“As writers, we need a culture that leaves us room for experimentation, risk-taking, and even mistakes. We need to preserve the possibility of good-faith disagreement without dire professional consequences.”
The document criticised “disproportionate punishments” given to targets of cancel culture by people attempting “panicked damage control”.
It added: “The forces of illiberalism are gaining strength throughout the world and have a powerful ally in Donald Trump, who represents a real threat to democracy.”
The letter said cancel culture had spread fear through the arts and media.
Within hours of the letter appearing on social media, a number of the signatories withdrew their endorsement. They included historian Kerri Greenidge and author Jennifer Finney Boylan, who tweeted: “I did not know who else had signed that letter. I thought I was endorsing a well-meaning, if vague, message against internet shaming. I am so sorry.”
