Anonymous has declared "total war" against Donald Trump. Above, vapor passes through a Guy Fawkes mask as a man smokes while joining supporters of the Anonymous movement who were taking part in the global Million Mask March protests in Union Square, New York, Nov. 5, 2014. Reuters/Elizabeth Shafiroff

In a series of tweets, the hacktivist group Anonymous warned President Donald Trump that he will “regret” the next four years.

Anonymous, which highly criticized Trump during his presidential campaign, responded to a tweet last Sunday in which he criticized CIA Director John Brennan and suggested he was “the leaker of Fake News.”

Trump’s tweet came after an unsubstantiated document alleging Russia had compromising information on the president was leaked by BuzzFeed. The document was believed to have been created by retired British intelligence officer Christopher Steele. The information had circulated among political and U.S intelligence groups before it was presented to Trump and former President Barack Obama.

In the tweets, Anonymous said it will find and release information on Trump’ personal and financial activities in Russia.

“Information doesn’t vanish, it is all out there,” said the group. “You have financial and personal ties with Russian mobsters, child traffickers, and money launderers.”

Anonymous also said their plans were not partisan saying, “We could care less about Democrats attacking you @realDonaldTrump, the fact of the matter is, you are implicated in some really heavy s---.”

After Anonymous warned the president, the group continued to tweet anti-Trump messages. Trump, who tweets often, did not respond to the group.

This isn’t the first time Anonymous threatens Trump. Last year, the group released a video on YouTube saying, “Dear Donald Trump, we have been watching you for a long time, and what we see is deeply disturbing.”