Have you heard of Zeon? Well, I heard about him today, here.
Short version: he makes cartoons. Which is what he got arrested for. Or rather, for hatespeech. In his cartoons.
While you might disagree with his views, the whole Charlie affair should still be fresh enough for people to remember what this freedom of expression stuff is supposed to mean.
The link above is from March 4 so by now this kind of case should have been properly discussed by the media. So, these are the search results (from today, March 26, 2015) for "Zeon" in the French mainstream media as defined by Wikipedia:
Le Parisien
They are close! But not quite the right artist...
Le Figaro
Le Monde
L'Équipe
Okay, I didn't really expect to find anything relevant there...
Les Échos
Libération
La Croix
L'Humanité
Charlie Wassissname again?