Just to put things into perspective after the attacks in Paris. Here's a study how many terrorist attacks in the EU were religiously motivated.
http://thinkprogress.org/world/2015/01/0...sm-europe/
http://thinkprogress.org/world/2015/01/0...sm-europe/
Quote: In 2013, there were 152 terrorist attacks in the EU. Two of them were “religiously motivated.” In 2012, there were 219 terrorist attacks in EU countries, six of them were “religiously motivated.”
In 2011, not one of the 174 terrorist attacks in EU countries in 2011 were “affiliated or inspired” by terrorist organizations. 2010, 249 terrorist attacks, three of them were considered by Europol to be “Islamist.” In 2009, of 294 terrorist attacks, only one was related to Islamist militancy – though Europol added the caveat, “Islamist terrorists still aim to cause mass casualties.”