Anonymous, the hacking collective, has declared “total war” against Republican presidential candidate Donald Trump, whom it describes as “deeply disturbing.” The group announced its OpTrump campaign, vowing to take down the billionaire’s property websites in Chicago on April 1.

“We have been watching you for a long time and what we’ve seen is deeply disturbing. You don’t stand for anything but your personal greed and power,” the group said in a video. “This is a call to arms. Shut down his websites, research and expose what he doesn’t want the public to know. We need you to dismantle his campaign and sabotage his brand.”

It’s not the first time the cybercollective has taken on Trump. Following his proposal to ban Muslims from entering the U.S. late last year, a hacking group connected to Anonymous, known as New World Hackers, managed to take down Trump’s website for about an hour. The group is calling for a widespread show of support for its fresh campaign, even from those who do not have savvy tech skills.

“This is a declaration of total war. OperationTrump engaged,” the group said.

Trump, who continues to maintain a sharp lead in national polling, has repeatedly brought controversy with his stances. He has said Islam hates America and has repeatedly promised to build a wall along the U.S.-Mexican border. His rallies have recently come under scrutiny for clashes between supporters and opponents, as well as instances of violence. Anonymous in the past has cited his views on immigration and perceived racism as cause for alarm.

Despite early predictions that his popularity would ultimately wane, Trump has so far won most of the early primary states. Texas Sen. Ted Cruz, Florida Sen. Marco Rubio and Ohio Gov. John Kasich trail behind.