The United States recently revealed that nearly 200 Americans had gone to Syria to join ISIL (Islamic State in Iraq and the Levant) and that about 20 percent of those had returned home. None of the returnees have been detected engaging in Islamic terrorist activity and not all those who went to work for ISIL went to fight. Some served with aid groups and other serviced as non-combat specialists (something ISIL had been calling for). While American Moslems comprise about three percent of all Moslems they were only about one percent of the foreign Moslems who went to join ISIL. American Moslems have long been less supportive of Islamic radicalism and are even less likely to provide financial support to Islamic terror groups but that is in part because the United States has been the most active nation in detecting and shutting down fund raising for Islamic terrorism. In the last decade and especially the last few year these efforts have convinced most Moslem nations to find and shut down such fund raising in their own territory, especially those that pose as “Islamic charities” but are, after not much investigation, revealed to be fronts for Islamic terror groups.
The United States won’t reveal details of how they monitor domestic charities or American Moslems attracted to ISIL calls to come and fight in Syria and Iraq. But it is now known that American intelligence agencies and even many police departments have become major users of special software for monitoring public web activity. A lot of recruiting and fund raising for Islamic terror groups is done on the web and all you have to do is make some effort (and have some ability to translate foreign languages a lot of this activity takes place in) to discover who, where and when.
Unfortunately the more capable Islamic terrorists and supporters now know to say as little as possible online or via cell phones. These require physical observation which is expensive, too expensive to watch all the thousands of suspects in Western countries. This has been discovered to be the case in many recent Islamic terror attacks in the West. Those responsible had been identified as pro-terrorist but even electronic surveillance had been dropped because there was no evidence of greater involvement or becoming an imminent threat. It requires over a dozen experienced operatives and over a million dollars a year to provide round the clock surveillance for one individual. This is a problem that will only get more attention if some of the returnees carry out a spectacular attack.