The inscription "I am Charlie" is written on the fronthead of a woman as she attends a gathering to pay respect for the victims of a terror attack against a satirical newspaper, in Paris, in Paris, Wednesday,... (Associated Press) 
 
 People hold up pens and a phone screen reading 'I am Charlie' in French as they take part in a vigil of people, including many who were French, to show solidarity with those killed in an attack at the... (Associated Press) 
 
 A woman holds a poster reading 'I am Charlie' with a rose, at a gathering in Nice, southeastern France, to express solidarity with those killed in an attack at the Paris offices of weekly newspaper Charlie... (Associated Press) 
 
 People hold candles during a gathering in support for the victims of a terror shooting in Paris, France, as they gather near EU headquarters in Brussels on Wednesday, Jan. 7, 2015. stormed the Paris offices... (Associated Press) 
 
 A woman holds up a pen and a phone with a sign on the screen reading "I am Charlie" in French as she takes part in a vigil of people, including many who were French, to show solidarity with those killed... (Associated Press) 
 
 People attend a demonstration in solidarity with those killed in an attack at the Paris offices of weekly newspaper Charlie Hebdo, at the French Consulate in Barcelona, Spain, Wednesday, Jan 7, 2015.... (Associated Press) 
 
 People gather to pay their respects for the victims of a terror attack against a satirical newspaper, in Paris, Wednesday, Jan. 7, 2015. Similar gatherings, including some silent vigils, took place at London's Trafalgar Square, in front of the Brandenburg Gate in Berlin, in Madrid, Brussels, Nice and elsewhere. Online, the declaration "Je Suis Charlie," or "I Am Charlie," replaced profile pictures on Facebook while Twitter users showed themselves with the slogan on signs with words of support for the 12 victims who were killed at Charlie Hebdo, a weekly newspaper that had caricatured the Prophet Muhammad.
– "Je Suis Charlie," read signs at silent vigils around the world as thousands of people gathered to express their horror and outrage at the terrorist attack on Paris satirical newspaper Charlie Hebdo. Around 35,000 people gathered in Paris' Place de la Republique, with many leaving candles and piles of pens at memorials to pay tribute to the 12 dead journalists, cartoonists, and police officers, the BBC reports. "These killers tried to kill not only people but also the idea of peace and debate," a Muslim schoolteacher carrying one of the newspaper's controversial cartoons at the Paris vigil told the Independent. "I won't let them do that and everyone in France won't let them do that. They had no right to use the name of Allah. Mohammed would be turning in his grave. Tonight we are all Charlie." Across France, the number of people at vigils ran into the hundreds of thousands, with vigils also taking place across Europe and worldwide. In New York City, where security has been stepped up at buildings such as the French consulate, a crowd gathered in Union Square sang the French national anthem and held pictures of the victims, reports CBS. There has also been a huge outpouring of support online, with hashtags like #IamCharlie trending, and social media users sharing images like a picture of a machine gun with the slogan "This is not a religion," the AP reports.