What is the Charlie Hebdo attack?

http://www.vox.com/2015/1/12/7533737/charlie-hebdo-cover

Gunmen wearing masks and bulletproof vests attacked Charlie Hebdo, a satirical weekly newspaper in Paris, around 11:30 am local time on Wednesday, January 7, during the newspaper's weekly editorial meeting. Twelve people were killed: eight journalists, including four well-known cartoonists; two police officers; a building maintenance worker; and a guest of the editorial board. Eleven more were injured, four of them seriously.

Police have identified two major suspects in the attack: brothers Saïd Kouachi, 34, and ChérifKouachi, 32, both of Paris. A third man sought by police, Hamyd Mourad, turned himself in at a police station near the Belgian border. Chérif Kouachi had a previous conviction for terrorism, in 2008, for helping smuggle fighters to Iraq. Saïd Kouachi had trained with al-Qaeda in the Arabian Peninsula, al-Qaeda's Yemeni affiliate.

The motive for the attack is still unclear. It was the deadliest, but not the first, attack on Charlie Hebdo. The left-wing, anti-establishment newspaper is part of a tradition of serious satire in France. It mocked everything — powerful politicians, pop culture, religion — but reserved particular glee for lampooning Islam and Muslims, often with raunchy cartoons. The newspaper's offices were firebombed in 2011 after they published cartoons of the Prophet Mohammed.

The January 7 attack led to an outpouring of support for Charlie Hebdo. At rallies in France and around Europe, thousands of people held up placards reading "Je Suis Charlie" (I am Charlie) or holding pens to represent the power of art and writing.

While the attack's motivation is still unknown, it has nonetheless sparked wide discussion, particularly in France, on issues of free speech and religious tolerance, on concern about the threat from extremist terrorists, and now with "reprisal" attacks against French mosques, about the treatment of the country's Muslim community.