This past Sunday over a million demonstrators took to Paris streets to remember those killed in an attack on French satirical publication Charlie Hebdo. World leaders like French President Francois Hollande, German Chancellor Angela Merkel, and Israeli Prime Minister Benjamin Netanyahu linked arms at the front of a procession on the city's streets, and the world watched on television. It was the biggest demonstration in the history of France.

GlobalPost co-founder Charles Sennott said the protests showed solidarity at a time when it was sorely needed.

"Something at the core of what we believe in is under attack."

Sennott said Charlie Hebdo has been a lightning rod for controversy, but that these demonstrations weren't about the content — they were about the freedom to publish that content.

"I don't like Charlie Hebdo. I don't like cartoons that insult somebody else's religion. And I don't think you could look at these cartoons any other way — on the Catholic Church, on Islam, on everything. They're vulgar, for sure. But I think we all would say we still love our right to look at them. We love that they are there, right there out in the world."

Sennott added: "Journalism — the stuff we do — is under direct attack."

Journalists are often dispatched to areas of conflict and extreme violence, and the recent beheadings of reporters by the Islamic State reinforce the dangers they face. Sennott said what happened in Paris overshadowed an equally horrific act in Nigeria earlier in the year.

On January 3rd, Boko Haram "went on a rampage in Nigeria, and they killed 2,000 people by many reports. This is Boko Haram unleashed," Sennott said. "Why is it we're not hearing about that? It is incredibly dangerous to cover Boko Haram. We have no journalists there because you're risking your life the second you go into that area of Nigeria. You're going to get kidnapped. You're probably going to get killed."

Sennott said between the attacks in Paris, and the slaughter in Nigeria, a new, concerted effort against the press was emerging.

'Where was President Obama? I mean, I know it was a big weekend for NFL viewing. That is American exceptionalism at work.'

"These Islamic militant groups are, I think, opening a new front very consciously, and that's what I think Paris drives home," Sennott said. "They're not just about striking fear among civilians, among innocent people on the streets. They're now going directly at what we consider our freedom of expression, and our right to inform through journalism. That's a new attack, and we've got to wake up."

Sennott said the twelve Charlie Hebdo journalists were martyrs for a cause that was also being fought in places like Saudi Arabia, China, Russia and Egypt.

"We are going to have to fight like hell for freedom of expression and for journalism."

Sennott was asked whether he thought President Obama, Vice President Biden or Secretary of State John Kerry should have attended Sunday's rally. He thought so.

"Where was President Obama? I mean, I know it was a big weekend for NFL viewing," Sennott said. "That is American exceptionalism at work. Somehow we think that because we face more security risks than others, we don't go."

>> To hear the entire interview with Charles Sennott, click the audio above. Charles Sennott is the cofounder of GlobalPost The GroundTruth Project, and regular Open Mic guest Mondays on Boston Public Radio with Jim Braude and Margery Eagan.