WASHINGTON US Secretary of State Marco Rubio has directed American diplomats to scrutinize the social media activity of certain visa applicants to bar those suspected of criticizing the US and Israel, according to a report Tuesday. The directive, issued in a March 25 cable to diplomatic missions, mandates that consular officers refer some student and exchange visitor visa applicants to the “fraud prevention unit” for a mandatory social media check, the New York Times reported, citing two US