Well, it makes sense in a certain sort of way. The Muslims in France have been fighting one for some time, now attempting to turn Dar al Harb into Dar al Islam.
It's what they do everywhere they spread. Just look at the once-Christian country of Lebanon for your prototype. Beirut was once called the Paris of the Middle east. Who knows how long it will take them to start calling Paris the Beirut of Europe?
While there are, indeed, a lot of Muslims in France, it's still a relatively low percentage: 7-9%
Religious Demographics Of France
True, enough to cause problems, but that only takes a handful of assholes. Most people, regardless of their religion, don't want to get involved in violence or anything else which will endanger their families.