The Louisville cadre of Black Lives Matter activists sent a letter to many downtown businesses demanding they “diversify” their employees. But at least one Cuban-American business owner objected to the threatening tone of the letter and posted his displeasure on Facebook. Fernando Martinez owns a restaurant group with several Hispanic eateries. He accused BLM of using “mafia tactics” and explained his position. “There comes a time in life that you have to make a stand and you have to really prove your convictions and what you believe in,” Martinez wrote in a public Facebook post. “… All good people need...