WASHINGTON (CN) – The former research director for embattled data analysis firm Cambridge Analytica told senators on Wednesday the company conducted “voter disengagement” efforts meant to keep minority voters at home during the 2016 presidential election.

Christopher Wylie, whose public comments set off the recent scandal over the data analytics firm’s use of Facebook data in its work with the Trump campaign, said Cambridge Analytica’s talks of plans to keep down minority turnout was a factor in his decision to leave in 2014.

Wylie’s public testimony before the Senate Judiciary Committee on Wednesday mirrors what he reportedly told House Democrats last month in a private briefing. He said Wednesday he was not directly involved in the programs, but offered to share documents with the committee on the undertakings after he consults with his lawyers.

He told senators on Wednesday that his former company’s work was fundamentally different than that of other data analysis firms.

“To be clear, the work of Cambridge Analytica is not equivalent to traditional marketing,” Wylie said. “Cambridge Analytica specialized in disinformation, spreading rumors, kompromat and propaganda.”

Much of Wylie’s testimony re-hashed old allegations against Cambridge Analytica, which gained access to more than 80 million Facebook profiles without users’ knowledge in an effort to build comprehensive psychological profiles of voters that could help microtarget political advertisements.

Wylie further raised concerns about the company’s close contact with Russian oil company Lukoil, telling senators that Cambridge Analytica CEO Alexander Nix sent the Russian firm a white paper Wylie penned detailing Cambridge Analytica’s work in the United States.

In addition, Wylie told senators Cambridge Analytica hired staffers with loose connections to WikiLeaks founder Julian Assange and conducted “black ops” services in which the company received hacked documents useful to clients.

“I can’t definitively say that this had any relation to the Internet Research Agency, for example,” Wylie said, referring to the firm at the heart of the Russian attempts to influence the 2016 election. “What I can say is that a lot of noise was being made to companies and individuals who are connected to the Russian government and for me that is a substantial concern.”

Wylie’s testimony built on hearings last month in which lawmakers heard from Facebook founder Mark Zuckerberg about his company’s efforts to cut down on data misuse. On Wednesday, Wylie called on lawmakers to seriously consider adopting regulations for social media companies because using the internet has become too ubiquitous for people to opt out if they are concerned about data privacy.

“If this is something that affects everybody, every day, then there should be some degree of accountability and public oversight,” Wylie said.

But Eitan Hersh, a professor at Tufts University, told lawmakers to be skeptical of Cambridge Analytica’s grand claims about its capabilities. Hersh said data analysts have strong incentives to overstate what their products can do.

Hersh told the committee that research has shown campaigns that use data analysis methods to predict the race of potential voters get it wrong a quarter of the time, making it unlikely Cambridge Analytica’s more ambitious undertakings are as accurate as it claims.

“The idea that Cambridge Analytica could use Facebook likes to predict personalities, then use those predictions to effectively target ads strikes me as implausible given what we know about the challenges of persuasion in campaigns,” Hersh told the committee. “No evidence has been produced publicly about the firm’s profiling or targeting to suggest that its efforts were effective or that it overcame the difficulties of persuasion that I just articulated.”

Hersh cautioned lawmakers it can be difficult to find the line between voter suppression or deception and simple negative campaigning. He also distinguished Cambridge Analytica’s work aimed at discouraging voters from instances of government-sponsored voter suppression.

“This is really different and it’s different because campaigns do things that are not nice all the time,” Hersh said. “If a Democratic campaign were to go and remind Trump voters of all of the moral failings in Trump’s past and say, don’t vote for him, is that demobilization or not? I don’t know.”

Sen. John Kennedy, R-La., also worried about companies and lawmakers overreacting to concerns about data misuse. The co-sponsor of legislation that would regulate how companies handle user data, Kennedy told the witnesses that at a certain point people have to be trusted to make their own decisions online.

“We can all agree that poison is being spread on social media,” Kennedy said. “Here’s the tough part: define poison. I don’t want Facebook censoring what I see.”