The NYPD is ramping up its patrols of local Jewish centers to brace for a potential national “Day of Hate” on Saturday. A leaked internal memo by the Police Department’s Intelligence and Counterterrorism Bureau says online extremist groups are “instructing like minded individuals to drop banners, place stickers and flyers, or scrawl graffiti as a form of biased so-called action” against Jewish people. The hateful posts warn of “antisemitic and white supremacist propaganda distributions and banner drops,” the Anti-Defamation League tweeted. In a statement, the NYPD said there are “no identified threats to New York City” but that “out of...