'Charlie Hebdo' Tributes By Cartoonists The World Over Are Pouring In To Honor The Tragedy — PHOTOS

By now, you've probably heard about the grisly attack on satirical weekly French newspaper Charlie Hebdo . Attacked by three armed assailants, 12 people at the paper's headquarters were shot to death Wednesday, in apparent retaliation for their publishing of unflattering cartoons of the Islamic prophet Muhammad. It's a horrifying tragedy that's galvanized international attention, and sparked broad discussion about media censorship, free speech, and bravery in the face of threats. And it's also triggered an outpouring of moving images from countless artists — Charlie Hebdo tributes from cartoonists all over the world poured in Wednesday, moving tributes to those who lost their lives, and the values they sacrificed for.

So far, this much is known about the attack: 12 people, two of them police, were killed by three gunmen. Among the dead was Charlie Hebdo 's editor Stephane Charbonnier, who had been receiving death threats and living under police protection for years, but refused to compromise his freedoms. In 2012, after the paper's office was the target of a firebombing, Charbonnier told Le Monde that he'd "rather die on my feet than live on my knees."

Here's are some of the most moving, poignant tributes to the victims, and to the institution of the free press, that have been circulating today. Be forewarned — while it's beautiful to see such solidarity, some of them are also wrenchingly sad.

The threat of physical, lethal violence over offended religious beliefs, specifically from cartoons, is reminiscent of previous incidents. Back in 2005, Danish newspaper Jyllands-Posten published cartoons of Muhammad wearing a bomb for a turban, among others, inflaming outrage against both the paper and the country, and leading to the bombing of the Danish embassy in Pakistan. and in 2007, Danish artist Lars Vilks' drawing portraying the Islamic prophet as a dog spurred further outrage. The latter was ultimately referenced in a threatening message received by authorities prior to two bombings in Stockholm in 2010.

The attack on Charlie Hebdo's offices has whipped up sympathetic support and solidarity in various different countries — in England, for example, mourners filled Trafalgar Square to remember the dead. It's also drawn widespread international condemnation, as you'd expect — President Obama, British Prime Minister David Cameron, and German Chancellor Angela Merkel have all given statements on the incident.

Images: Rob Tornoe/Twitter