Haha, I just remembered an American acquaintance, a lieutenant in the KKK. Every day was filled with verbal hate every other hour. Had a very well disciplined dog, a doberman warlock, wouldn't even eat his food if you didn't tell him to and loved to terrorize the cat by gently sticking its head in his mouth. That dog was very well trained, not just in discipline but to be a violent racist as well. Couldn't easily take him outside and when you did the leash was made of chain links, if he saw someone with so much as a tan he'd lose all control, no stopping him. I wonder who was more violent, the owner or the dog. It should be noted that the owner didn't train the dog but rather someone more senior to him.
I see a slightly similar relationship between Islamic extremists and the legitimate, recognized, fundamentalists. One is at fault for the other but not entirely, inaction is the problem here.
How would a vicious dog on the loose be dealt with? It would be put down by the city police before it could hurt anyone, its owner lectured by the legal authority and perhaps even fined or jailed. Not surprised if that's happened by now.
In other words, people need to wake up and deal with ISIS in Syria and elsewhere, and not just them, full in now before it's too late. It's a shame that it takes a tragedy like what happened in France for people to concern themselves with what goes on in the rest of the world.