The millions of Syrian refugees in camps are increasingly finding the violence they were fleeing is following them. The Islamic terrorist groups are sending men and women to the camps posing as refugees. Security in these camps is provided by the equivalent of peacekeepers in the form of local police and soldiers. Such security usually does not prevent gangsters or Islamic terrorists from getting in. Thus once registered inside the camps the refugee terrorists get in touch with fellow terrorists outside the camps who have weapons and access to smugglers to get new terrorist recruits from the camps out and back to Syria. The terrorists know from past experience (several decades’ worth) that with enough armed followers registered and legally inside the camps they can eventually take control of parts of the camps. The terrorists often cooperate with or take over criminal gangs or networks already in the camps. Some of the more extreme groups (like ISIL) go too far, and attract unwanted attention, by persecuting non-Moslems in the camps. Usually they are Christians and unlike most others the Christians will complain to camp officials and media and religious organizations outside the camps.
There are about four million registered Syrian refugees in Turkey, Lebanon and Jordan. There are over five million refugees in all because many do not bother to register and live outside the camps. About 45 percent of the refugees are in Turkey, 35 percent in Lebanon, 25 percent in Jordan and the rest in several other Middle Eastern nations. Turkey and Jordan will crack down hard on illegal activity inside the camps but Lebanon is more chaotic because of decades of sectarian fighting that has never really ended.
The criminal gangs deal with all sorts of vices, including persuading or forcing refugee women to be prostitutes. Drugs and weapons are available as well as a black market for just about anything. The more gang activity there is the easier it is for the Islamic terrorist groups to get established. To further complicate matters for peacekeepers or local police the Islamic terrorist activity inside camps is usually a small part of criminal activity in general. So in many cases the Islamic terrorists hide in plain sight among the more numerous non-religious criminals.