The activist hacking group Anonymous launched an operation against Republican presidential front-runner Donald Trump on Friday taking down the website for Trump Tower in New York City.

Shortly after the hack, a Twitter account associated with Anonymous group confirmed the attack, saying the takedown was a “statement against racism and hatred.”

Earlier in the week, the same group posted a video on YouTube, warning Trump to “think twice” before he speaks.

“Donald Trump, it has come to our attention that you want to ban all Muslims from entering the United States,” a voice read. “This policy is going to have a huge impact. This is what ISIS wants. The more Muslims feel sad, the more ISIS feels they can recruit them.”