This past weekend, Jewish students at Cornell were faced with yet another threat to their ability to participate in campus life – and exist. An online message poster threatened they were “gonna shoot up” the Jewish Living Center on campus. Other users — with handles “jew evil,” “jews need death,” and “kill jews” — piled on. The posts then went viral. The furor reached a point where, yesterday, Cornell canceled classes due to “extraordinary stress” from the events. Of note, law enforcement responded almost immediately, and the Cornell administration did too, in no small part thanks to the efforts of...