Thomas Barrack, the billionaire fundraiser and longtime friend of former President Donald Trump, pleaded not guilty on Monday to federal charges that he illegally lobbied the U.S. government on behalf of the United Arab Emirates, obstructed justice, and lied to the FBI.

As the 74-year-old entered the Brooklyn courthouse, a protester holding up a sign that read “Dirty Traitor” shouted, “It’s our democracy, not yours! Traitor!” followed by an expletive.