An official memo said social media vetting would be stepped up for student and foreign exchange visas, which would have "significant implications" for embassies and consulates. Responding to the move, China called on the US to protect international students. The memo also said the state department was preparing for an "expansion of required social media screening and vetting" applicable to all student visa applications. Critics say the new policy on social media vetting represents a further violation of the rights that are supposed to be enshrined by the First Amendment in the US Constitution. Watch: "Without us, Harvard is not Harvard", says international student on visa