SIAs are noncitizens who, based “on an analysis of travel patterns,” are “known or evaluated to possibly have a nexus to terrorism” who “potentially poses a national security risk to the United States,” the U.S. Department of Homeland Security explains. Having an SIA designation does not necessarily mean the individual is a terrorist, but their travel pattern “indicates a possible nexus to nefarious activity (including terrorism) and, at a minimum, provides indicators that necessitate heightened screening and further investigation,” DHS says.