From the story by Michel Warschawski here:
Nevertheless, broadly speaking, Charlie was part of my political environment. That is, until Philippe Val, the chief editor, expelled one of the founders of the weekly and it's most popular caricaturist, Bob Sine, falsely accused of being an anti-Semite. The expulsion of Sine was clearly a signal of kneeling to the dominant ideology that was using "anti-Semitism" in order to shut the mouth of journalists critical to Israel. A couple of years later, Philippe Val was appointed by Nicolas Sarkozy [sic] as general director of one of the national radio channels. No comment…
As an act of solidarity with Sine, I joined the editorial staff of "Sine Hebdo", a new satirical weekly he opened together with other former journalists of Charlie Hebdo who left, as a protest of Val's decision.