“To facilitate this vetting, all applicants for F, M and J non-immigrant visas will be asked to adjust the privacy settings on all their social media profiles to ‘public’”, the official said. “The enhanced social media vetting will ensure we are properly screening every single person attempting to visit our country.”
and if you don’t have one?
To them that is already suspicious enough to not let you in the country and put you on some list of known terrorists.