WASHINGTON, DC - AUGUST 12: Jason Kessler (C), who organized the rally, speaks as white supremacists, neo-Nazis, members of the Ku Klux Klan and other hate groups gather for the Unite the Right rally in Lafayette Park across from the White House August 12, 2018 in Washington, DC. Thousands of protesters are expected to demonstrate against the 'white civil rights' rally, which was planned by the organizer of last yearÕs deadly rally in Charlottesville, Virginia (Photo by Mark Wilson/Getty Images)

WASHINGTON (AP) — White nationalists and supremacists are building thriving, macho communities across social media platforms like Instagram, Telegram and TikTok. The accounts are using coded hashtags and innuendo to rile up thousands of followers on divisive issues like abortion and recent mass shootings. Those are the issues the department of Homeland Security warned Tuesday might drive some extremists to violently attack public places across the U.S. The heightened concern comes just weeks after a white 18-year-old who claims he was radicalized on internet chatrooms entered a supermarket in Buffalo, New York, with the goal of killing Black patrons. He gunned down 10.