SAN FRANCISCO (CBS SF) — Saying he did not want anyone to use Facebook “to undermine democracy,” Facebook CEO Mark Zuckerberg on Thursday announced his company would turn over 3,000 controversial ads purchased by Russians to Congressional investigators.

Zuckerberg addressed the criticism leveled at his social platform after it was revealed earlier this month that hundreds of phony Facebook accounts, likely run from Russia, spent about $100,000 on ads aimed at stirring up divisive issues such as gun control and race relations during the 2016 campaign.

The chairman of the Senate intelligence committee said that Facebook executives should testify as part of its probe into Russian meddling in the U.S. election, and that the social media giant “seems to have been less than forthcoming” with Congress.

“Facebook seems to have been less than forthcoming on potentially how they were used,” said Sen. Richard Burr, R-N.C., adding that it’s “just a question of when, and potentially the scope of what that hearing would be.”

Zuckerberg, on his first day back after a paternity leave following the birth of his second child, took to Facebook Thursday to make the announcement.

“The integrity of our elections is fundamental to democracy around the world,” he said. “Our teams have found and shut down thousands of fake accounts that could be attempting to influence elections in many other countries, including recently in the French election…I wish I could tell you we are going to be able to stop all interference, but that would’t be realistic.”

Zuckerberg admitted Thursday that at first they didn’t think the Russians actually bought ads.

“We have been investigating this for many months, and for a while we had found no evidence of fake accounts linked to Russia running ads,” Zuckerberg explained.

But on Thursday, he confirmed there were paid ads: more than 3,000 of them.

“When we recently uncovered this activity, we provided that information to the special counsel,” Zuckerberg said. “We also briefed Congress — and this morning I directed our team to provide the ads we’ve found to Congress as well.”

On Thursday, he said Facebook techs were still looking for any other Russian accounts, and he vowed more transparency going forward.

“Not only will you have to disclose which page paid for an ad, but we will also make it so you can visit an advertiser’s page and see the ads they’re currently running to any audience on Facebook,” said Zuckerberg.

Zuckerberg hinted that the company may not provide much information publicly, saying that the ongoing federal investigation will limit what he can reveal.

“As a general rule, we are limited in what we can discuss publicly about law enforcement investigations, so we may not always be able to share our findings publicly,” he said.

Hemu Nigam is a cyber-security expert. He told KPIX 5 he’s not buying Facebook’s good guy routine. He said the company is simply trying to save face

“The real question we should be asking is, ‘Why is Facebook talking about this now?'” said Nigam.

He said the changes Facebook is promising could have been done last year. The company is only acting now because they’re in trouble.

“I don’t think it’s so much a trouble in the legal sense, but what you do have is a major reputation issue that they’re going to have to deal with,” said Nigam.

He says Facebook’s actions send a message: companies can act and the public will expect them to so.

“This should be a message to the entire industry: that you can be proactive,” said Nigam. “And in fact, it’s actually in today’s day and age, a necessity for doing business internationally.”

It should be noted that some lawmakers have been calling for tighter regulation of internet ads. By getting out front and promising to self-regulate, Facebook may be trying to head off that effort.

While KPIX 5 doesn’t have the official request from Congress, remember that one theory is that the trump campaign shared polling data with the Russian government so the Russians would know exactly whom to target with their fake Facebook and Twitter accounts.

If this new data from Faceboook shows that ads were programmed to be very focused — say, to only appear to users in a certain county in Wisconsin — that would support the theory that Russians were getting help from sophisticated professionals.