The FBI and Department of Homeland Security have issued a bulletin to law enforcement agencies to warn them of the "continuing trend of Western youth being inspired by [the Islamic State] to travel to Syria to participate in conflict."
"The youth factor is the most important part of this," said Karen Greenberg, the director of the Center on National Security at Fordham Law School. "There's a tone of teenage rebellion in it."
While social media is helping ISIS recruit new members, many of the potential recruits are being caught because they're posting Facebook and Twitter messages about their plans to become jihadists.
Special: Find Out Everything You Need to Know About the Rise of ISIS — Click Here
According to Director of National Intelligence James Clapper, an estimated 180 Americans have either traveled or tried to travel to Syria's civil war,
reports The Wall Street Journal, and some of those people and other potential ISIS supporters do have a few similarities.
Many are in their late teens or early 20s, and use social media sites like Facebook and Twitter to support ISIS, and recruiters from the extremist jihadist group are adept at using social media to tailor messages toward those people.
But potential recruits come from many walks of life. Some are raised as Muslims, while others converted. As well, the ISIS message is reaching both married and single people, men and women, American citizens as well as immigrants, and people both rich and poor are showing their support for the jihadist movement.
"An interesting fact on some of the individuals that we investigate for support to [ISIS] is the lack of a singular profile," Michael Steinbach, head of the FBI's counterterrorism division, told a recent congressional hearing. "We find citizens, legal permanent resident aliens, some folks that are overstaying their visa. There's actually quite a diversity of those individuals who for one reason or another state an intent to harm the United States."
Overall, nearly 30 people have faced federal prosecution in the last 18 months in ISIS-related cases, and more are being arrested, including three Brooklyn, N.Y., men
arrested last week on charges they were plotting to support ISIS. According to the FBI, there are open ISIS investigations in all 50 states.
"All kinds of different people are being radicalized," Matthew Levitt, director of the Stein Program on Counterterrorism and Intelligence at the Washington Institute, told The Wall Street Journal. "Some are loners seeking more of the belonging and adventure. Some have ethnic-identity issues. Some are drawn to the radical ideology."
Many of those trying to join ISIS are teens and young adults who are trying to hide their travel plans from their parents, including Brooklyn defendant Akhror Saidakhmetov, 19, whose mother took away his passport because she feared he was going to travel to Syria to join ISIS.
Not all cases involve people wanting to go to Syria, but also include people allegedly interested in launching domestic attacks, such as Christopher Cornell, 20.
Cornell, from Ohio, was arrested after he allegedly tweeted pro-ISIS messages about plans to detonate pipe bombs and to shoot officials at the U.S. Capitol building.
"This is a dynamic threat," said Marc Raimondi, a spokesman for the Justice Department's National Security Division. "There's not one particular path to radicalization; there's not one particular path to violence."
Special: ISIS: Everything you need to know about the rise of the militant group — Click Here