Listen to this reasoning:

But there are several reasons why it’s worth waiting until all the facts are known before making too strong a link between the attacks and the refugee crisis. The first is a general one: on at least 12 occasions, Isis has actually criticised refugees for fleeing to Europe. “For those who want to blame the attacks on Paris on refugees, you might want to get your facts straight,” wrote Aaron Zelin, an analyst of jihad, in an online commentary about the 12 outbursts. “The reality is, [Isis] loathes that individuals are fleeing Syria for Europe. It undermines [Isis’s] message that its self-styled caliphate is a refuge.” It’s therefore unlikely that the vast majority of Syrians fleeing to Europe are Isis supporters, since their actions are in obvious contravention of the group’s creed.

http://www.theguardian.com/world/2015/nov/15/why-syrian-refugee-passport-found-at-paris-attack-scene-must-be-treated-with-caution

No-one is saying the refugees are ISIS supporters. They are saying that ISIS supporters could be among the refugees.

Aaron Zelin and The Guardian are clearly idiots.