NEW YORK (CBSNewYork) — As President Barack Obama announced the first attacks on the Islamic State group in Syria, NYPD Commissioner Bill Bratton has said his department is preparing for the possibility that some of the 100 Americans who have joined ISIS could come back to the New York area.

So who are the Americans who authorities say are out to attack their own country? As CBS 2’s Tony Aiello reported, the FBI said it is watching them and stopping them is a priority.

The FBI is “trying to identify those who want to travel to Syria to fight, who are there fighting, and who may be coming back to Western Europe and to North America,” said FBI Director James Comey.

Comey said the FBI is “tracking” more than 100 Americans both overseas and at home.

“We infiltrate the communities with informants, with undercover agents. We use wiretaps. We monitor social media and emails,” said Robert Strang of the Investigative Management Group.

Strang said terror groups are trying to extend their reach by recruiting westerners and threatening the homeland.

This week, ISIS released an ominous message to America and its allies, saying in Arabic, “You will not feel secure even in your own bedrooms.”

“There’s no question they want to make a scene; they want to be as horrific, as terrible, as bloody as they can be to make a point,” Strang said.

The terrorist tough talk helps ISIS boost its prestige in the jihadist world, according to the FBI.

“This is a group that aspires to be a leader of the global jihad,” Comey said.

Among the Americans who have been radicalized is Moner Mohammad Abusalha, a Florida native, who committed suicide in a bombing in Syria in May. Also on the list is Shannon Conley of suburban Denver, who pleaded guilty this month to planning to travel to Syria and aid ISIS.

Experts said there is no one path to radicalization, but in general, “someone who is troubled and might seek this kind of outlet in a perverted search for meaning in their lives,” Comey said.

The NYPD said it is looking at a “small number” of people who may have traveled to Syria with an agenda of aiding ISIS.

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