It was typical for the anonymous account, which traffics in far-right content and a conspiracy theory known as QAnon, some of whose adherents think that satanic pedophiles control the “deep state.” The Federal Bureau of Investigation recently labeled QAnon a potential domestic terror threat.
Still, that did not stop others, including a Republican congressional candidate, from quickly picking up the hashtag and tweeting it. Within a week, hundreds of QAnon believers and “MAGA” activists had joined in, posting memes and bogus reports to undermine the complaint by a government whistle-blower that President Trump had pressed Ukraine’s leader for dirt on former Vice President Joseph R. Biden Jr. and his son.
Then Mr. Trump tweeted the hashtag himself.