Foreign students studying in US, and they have only online classes have to leave US and go back to their countries.
Because of Corona Pandemic, many classes in colleges in US have been switched to online classes. The most of classes in Harvard and South California University are now online classes. Those foreign students studying US cannot get F-1 visa to stay in US and have to go back to their countries.
SEVP modifies temporary exemptions for nonimmigrant students taking online courses during fall 2020 semester
Nonimmigrant F-1 and M-1 students attending schools operating entirely online may not take a full online course load and remain in the United States. The U.S. Department of State will not issue visas to students enrolled in schools and/or programs that are fully online for the fall semester nor will U.S. Customs and Border Protection permit these students to enter the United States. Active students currently in the United States enrolled in such programs must depart the country or take other measures, such as transferring to a school with in-person instruction to remain in lawful status. If not, they may face immigration consequences including, but not limited to, the initiation of removal proceedings.