The hacker and activist collective Anonymous, which wasn’t a heavy-hitter during the presidential campaign, has now warned Donald Trump that he is going to “regret” the next four years.

The group made the threat in response to Trump’s tweet earlier this week suggesting that outgoing CIA Director John Brennan may have been the leaker of what Trump called “fake news” — the revelation of an unsubstantiated report by a former British spy that claims Russia has compromising information on the president-elect that could be used to blackmail him.

Anonymous vowed that it will seek out and release damaging information on Trump’s activities and finances linked to Russia. “Information doesn’t vanish, it is all out there,” the group said, promising to reveal details on “financial and personal ties with Russian mobsters, child traffickers, and money launderers.”

.@realDonaldTrump you have financial and personal ties with Russian mobsters, child traffickers, and money launderers. — Anonymous (@YourAnonCentral) January 16, 2017

This isn't the 80's any longer, information doesn't vanish, it is all out there. You are going to regret the next 4 years. @realDonaldTrump — Anonymous (@YourAnonCentral) January 16, 2017

The group indicated that planned attacks weren’t partisan but motivated by a drive to reveal that Trump is involved in “some really heavy shit.”

We could care less about Democrats attacking you @realDonaldTrump, the fact of the matter is, you are implicated in some really heavy shit. — Anonymous (@YourAnonCentral) January 16, 2017

Anonymous threatened disclosures as well during the presidential campaign, saying Trump stands only for “personal greed and power.” At one point alleged members released what was supposed to be a Trump cell phone number and Social Security number.

But Russian hackers at the behest of President Vladimir Putin reportedly stole the group’s typical thunder by exposing embarrassing Democratic National Committee emails, according to a U.S. investigation. Trump and the Republicans were unscathed in the effort to steer the election Trump’s way, according to U.S. intelligence officials.

Trump hasn’t responded to the Anonymous tweets.