(Reuters) -New York Attorney General Letitia James on Wednesday said her office is investigating social media companies the Buffalo grocery store gunman used to plan, promote and stream the attack that left 10 dead. James in a Tweet said her office will investigate Twitch, 4chan, 8chan and Discord along with other platforms the shooter used to amplify the attack. “This terror attack again revealed the depths and dangers of these platforms that spread and promote hate without consequence,” she said. “We are doing everything in our power to stop this dangerous behavior now and ensure it never ha…