It starts with a tweet. The recruit has been slowly and carefully chosen from his local community -- perhaps at a mosque, or gym, or cafe -- by an al Qaeda recruiter, aiming to send a Westerner to fight alongside radicals in Syria. According to a defector from the ranks of the Islamic State in Iraq and Syria (ISIS) -- whose stronghold in the Syrian town of Raqqa punishes smokers and insists women wear a veil --  the jihadist group runs a series of internet welcome chat groups to begin the process of indoctrinating and filtering potential recruits from outside Syria.
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Islamist defector says Twitter, Google Chat and Skype used to recruit foreign fighters
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West is concerned foreign fighters will return to home countries with terrorist plots
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Defector says foreign fighters are recruited over weeks
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He says one recruit wanted to see an execution video; others asked about marriage
I can't talk on @placeholder, as everything is written down, so they can monitor everything."