North Dakota authorities filed criminal trespass and mischief charges against Green Party presidential nominee Jill Stein after she spray-painted a construction vehicle during a protest this week against the Dakota Access Pipeline. While attending the rally, Stein was asked by activists to leave a message at the protest site. She obliged by writing “I approve this message” in red paint on the blade of a bulldozer. The pipeline has been a lightning rod for controversy, especially among environmentalists, who’ve protested against its construction for several months now. Stein was arrested during the 2012 election after trying to enter a presidential debate at Hofstra University.