Schroepfer, who’s the latest to give evidence to U.K. lawmakers in the wake of revelations concerning Cambridge Analytica, was forced to defend numerous activities of his company.

One of the most heated exchanges came between Julian Knight and Schroepfer. The Conservative minister said Facebook was a “morality-free zone,” destructive to privacy, and not an innocent party that was wronged by Cambridge Analytica. “Your company is the problem,” he said.

But Schroepfer also made commitments that were well-received. Facebook said it will make sure political ads on its platform will be vetted and transparent in time for England and Northern Ireland’s 2019 local elections, that only verified accounts will be allowed to pay for political ads, and users will be able to view all promotions paid for by a campaign — not just those targeted to them based on their demographic or “likes.”

“We’re going to provide a searchable archive of all of those ads, and show who paid for them,” Schroepfer said.

The CTO said Facebook ads would be labeled as “political,” and that all promotions would be available to be searched in an archive the social network will keep available for seven years. Data in the archive will also show how many people may have seen each ad, and how much was paid for their display.

Damian Collins, head of the committee, asked whether Facebook users can choose not to see ads from specific political parties or campaigns. Schroepfer said “there’s no category-by-category opt-out,” but that individuals could choose not to see specific ads once they’ve been shown them once.

Collins was not impressed. “That’s a weak tool to stop people getting messaging they don’t want,” he said, and suggested he thought political advertising and related user preferences should be treated very differently to those concerning general consumer interests.

Collins asked why Facebook didn’t spot Russia’s use of the social network to target voters sooner. “We were slow to spot that,” Schroepfer said, adding, “I’m way more disappointed in this than you are.” The claim prompted laughs from around the interview room and a subsequent apology from the CTO. “It’s a high bar,” Collins replied.

Schroepfer said that while he was giving evidence, “we’ll likely be blocking hundreds of thousands of attempts by people from around the world trying to create accounts with automated systems.”

Knight also suggested the social network tried to prevent the press telling the truth about its business. “I am sorry that journalists feel that we’re trying to prevent them from getting the truth out,” Schroepfer said.

The parliamentary committee interviewing Schroepfer has recently heard evidence from whistle-blower Christopher Wylie, former Cambridge Analytica executive Brittany Kaiser, and Kogan, the researcher who shared Facebook user data with Cambridge Analytica.

The CTO said Facebook did not know until last year that the person it hired to be a social psychology researcher — Joseph Chancellor — had co-founded Global Science Research, the company with Aleksandr Kogan that obtained information on Facebook users via a personality quiz app. Kogan later gave that information to Cambridge Analytica.

Ousted Cambridge Chief Executive Officer Alexander Nix refused to appear before the committee earlier this month, after previously agreeing to. Facebook Chief Executive Officer Mark Zuckerberg also said in March that he will not appear and that Schroepfer would fill this request.