U.S. Citizenship and Immigration Services (USCIS) updated their policy, effective August 9, 2018, on how "unlawful presence" is accrued by international students and scholars in F and J visa classifications. A period of time in unlawful presence has serious consequences and can affect your eligibility to remain in or return to the United States.
Today, the Supreme Court issued its decision in the travel ban case, upholding the ban in a 5-4 decision by the Chief Justice, with Justices Breyer, Kagan, Sotomayor and Ginsburg dissenting. The countries affected by the ban are Iran, Libya, Yemen, Syria, Somalia, Venezuela and North Korea. The travel restrictions, which have been in effect since December 4, 2017, are described here.