ATLANTA » A threat by Anonymous to unmask at least 1,000 members of the Ku Klux Klan might have come to fruition Sunday when the names of notable politicians, supposedly affiliated with the hate group, started coming to light.

A list of nine politicians, including U.S. senators and mayors, was posted late Sunday on a data dump site, well ahead of the Thursday launch date Anonymous had set to unmask the members of the domestic terrorist group.

But by midday Monday, the group was using Twitter to back away from that list.

“This account has NOT YET released any information. We believe in due diligence and will NOT recklessly involve innocent individuals,” they wrote in one tweet.

That was followed a half-hour later with: “The anons at the helm of this initiative vouch ONLY for the dox list that will be released from this Twitter account on November 5 2015.”

Late last month, Anonymous — a fluid group of hacker activists with no real leadership or centralized base — announced “Operation KKK Hoods Off 2015,” claiming that it would reveal the identity of the Klan members. They gathered the information through an unsecured Twitter account associated with the group.

The group launched a similar attack in 2012 with Operation Blitzkrieg, which they say exposed neo-Nazis in the United States and Europe.

On its website, Anonymous has a countdown clock ticking down to Nov. 5, which is also the first anniversary of the grand jury decision not to prosecute Darren Wilson, the white Ferguson, Mo., police officer who shot and killed Michael Brown.

Brown’s shooting in August 2014 triggered the Black Lives Matter movement.

But on Sunday night, names started appearing on PasteBin, a site used to share and store text and computer code. By Monday afternoon, the site had listed the names, spouses and locations of four U.S. senators and five mayors.

The Atlanta Journal-Constitution is not listing the names.

“I think this is pretty irresponsible to say the least,” said Mark Pitcavage, director of the Anti-Defamation League’s Center on Extremism. “You cannot make an accusation that someone is a member of a hate group without providing substantial evidence.”

Pitcavage said he is awaiting the release of the full list, but doubts that a true list of KKK members actually exists.

“There is no one Ku Klux Klan. There are 40-odd KKK groups in the country and none of them have anywhere close to 1,000 members,” Pitcavage said. “This raises the question of what sort of list they could have gotten. Is this a list of people who follow Twitter accounts? Did they get hold of a mailing group?”

Pitcavage, who tracks individual white supremacists through the ADL, said while they have “many individual members identified, we don’t have 1,000 members identified.”

“So we have to wait and see what they actually have before we can evaluate this,” Pitcavage said.

The Southern Poverty Law Center, an Alabama-based organization that tracks the movement and activity of hate groups, would not comment.