SAN FRANCISCO — Twitter said Sunday it had banned the personal account of Rep. Marjorie Taylor Greene for multiple violations of the platform’s COVID-19 misinformation policy, the latest strike against the firebrand whose embrace of conspiracy theories has been called “a cancer” for the GOP..

The Georgia Republican’s account was permanently suspended under the “strike” system Twitter launched in March, which uses artificial intelligence to identify posts about the coronavirus that are misleading enough to cause harm to people.