Rep. Tim Bishop (D-N.Y.) said in a recent speech that of the 100 or so radicalized U.S. citizens who have traveled to the Middle East to fight with ISIS, "up to 40" of them have returned and are now back on American soil.
"One of the concerns is the number of U.S. citizens who have left our country to go join up with ISIS," Bishop said. "It is also believed that some 40 of those who left this country to join up with ISIS have now returned to our country."
According to the congressman, these 40 individuals "are under FBI attention and surveillance. So they are known and being tracked by the FBI."
The White House reported last week that "U.S. intelligence agencies have not detected any plots by Islamic State militants to stage an attack on U.S. soil." Many Republican lawmakers, however, have been calling for the Department of Homeland Security to up its manpower in vulnerable places like the American border with Mexico.