ROSARIO, Argentina – Despite restrictions on hate speech on social media in Spain, a trending hashtag calling for Catholic priests to be burned alive was not removed for violating rules against posting calls for violence. The invitation to #FuegoAlClero, or set fire to the clergy, was first issued by several pro-Marxist accounts, originally in defense of a bill to reform Spain’s education system that would put the state in control of religious instruction in public schools and limit support for thousands of Catholic schools, which could lead to their closure. However, the trending topic was accompanied by calls to burn...