First of I and we are not responsible for their savagery.
These extremist minded radicals are scums of the Earth, lower than beasts, they have been wrecking our Muslim lands, killing off a 100 people per suicide bomb blasts, blowin' themselves up in Masjids, streets, marketplaces and just about anywhere.
We are wrecked by this virus, their ideology is nothing but destruction. Just look at Boko Haram (translation: 'Secular Educated is Haram') they bomb anyone and anything, and wants to keep on doing shit like this until they get their 'Islamic State governed by the Sharia' that they envision.
Al-Shabaab over at Somalia, Al-Qaeda in Algeria, Yemen, Iraq (they all have different names under the same banner) have blowing stuff up regularly, usually targeting Juma prayer-goers.
Then we have these scums over in Afghanistan and in Pakistan called the Taliban, and their affiliates of Sipah e Sahaba and Lashkar e Jhangvi, they all call for unlimited bomb attacks, killings, beheadings you name it. They all shun education and envision the same 'Islamic State governed by the Sharia' through absolute brutality and savagery. Their leaders openly confess and declare more of this to come because 'God is on their side'.
Think I am making this up, well inquire and read it up yourself, they dress in 'Islamic' clothes, but show Ikhlaq worse than animals. They clearly contradict our classical Scholars, the Prophet's Family and his Companions as many of them were great Scholars, mastering a variety of Sciences and what not. Them on the other hand permit this 'Kufr' to be blown apart, along with other savagery.
One does not, and will not establish a generous state that the Prophet established through the brutality they are upto. What we can do is distance ourselves from these people, as far and wide as possible, as their Aqeedah is very wrong clearly. We should also tell the police whenever we get the doubt. Two potential train bombers (they were in planning for now) were caught in Canada since their immediate Muslims community told them Police to keep a close watch on them.
Even the elder Boston Bomber got kicked out of Juma Sermons for showing Extremist tendencies, in these cases, we must distance ourselves, shun them, condemn them, and even alert the authorities. These scums have been wrecking our lands, and now are wrecking the West, with same old brutality and weird ideologies deeply scarring the image of Islam in the meantime.
May Allah (swt) protect us from their destructive ideologies.