Cartoonists around the world put pencil to paper in solidarity with the Charlie Hebdo artists slaughtered in Paris, admitting their own fear of being targeted but vowing they would not be silenced.
In the small world of political satire, many cartoonists knew the journalists at the French weekly magazine who were among 12 killed by suspected Islamists on Wednesday.
They expressed their anguish and deep anger at the killings in the way they know best.
One of the pictures that quickly went viral on the Internet was by Dutch artist Ruben L. Oppenheimer, showing a plane flying into two pencils standing erect, reminiscent of the Twin Towers in New York.
Another cartoon, by Australia's David Pope, showed a picture of a gunman with a smoking rifle standing over a body, bearing the caption "He drew first".
"Ultimately people who carry out these attacks can't defeat ideas through these means and they won't succeed," Pope wrote.
He admitted the attack "hit a nerve", but said: "Our task is to keep doing what we do... focus our satire on those in power and those who seek to wield power in ugly ways."
Newspapers across the world republished Charlie Hebdo's cartoons in solidarity, including one of its most famous of the Prophet Mohammed in tears, lamenting: "It's hard to be loved by jerks."
One notable exception was Jyllands-Posten, the Danish newspaper which sparked worldwide protests with its publication of cartoons depicting Mohammed in 2005.
Kurt Westergaard, who drew one of the most contentious of the images, showing Mohammed wearing a bomb instead of a turban, admitted he was scared.
"The fear from yesterday will not disappear for a very long time," he told BBC radio, but said he hoped cartoonists would work to fight "self-censorship".
"Everybody is afraid and I understand that, but we have to be brave and go on with our criticism and that means making cartoons," he said.
"A good cartoonist who works with satirical cartoons, he must be a kind of an anarchist who attacks all authorities if they abuse their power, their influence," Westergaard said.'Inherent risk in the work'
Charlie Hebdo had long been in confrontation with Islamists for allegedly insulting Islam, but many other satirists around the world face threats.
Algeria's top cartoonist Dilem, who has been convicted for offending President Abdelaziz Bouteflika and has also been threatened by Islamists, said he never went to his newspaper office but worked from home.
"I know there is an inherent risk in the work that we do today. I know you can't joke with these people," he told Radio France International, but insisted he would continue.
One of Africa's leading political cartoonists, Kenya-based Gado, has also been threatened over the years.
He showed his solidarity with Charlie Hebdo with a drawing of a hand with a raised middle-finger in the form of a pencil, alongside the #JeSuisCharlie slogan.
The 45-year-old said it was important to "reject and condemn this act, but also show defiance that we should not be cowed".'They've beaten us'
Editors from Hong Kong to Washington published some of Charlie Hebdo's cartoons depicting the Prophet Mohammed, the ones that have most enraged Islamists.
But others remain deeply cautious.
Britain's Independent newspaper filled its front-page on Thursday with a picture of a bloodied copy of Charlie Hebdo with a hand coming out of it bearing a pen and raising the middle finger.
But editor Amol Rajan decided against publishing the cartoons themselves, saying: "It would have been too much of a risk to unilaterally decide in Britain to be the only newspaper that went ahead and published."
Israeli cartoonist Amos Biderman, who works for left-leaning newspaper Haaretz, made no secret of the fact that he had now been cowed into silence.
"The bad guys have won... They've beaten us big time in the battle for freedom of expression," he wrote.
"Now there is no cartoonist or publisher who would dare start up with them. They're all trembling in fear," he said.
He added: "The journalists at Charlie Hebdo... are few and far between, and truly courageous. I'd been following their editions, and I knew it would end badly."