Facebook Chief Executive Officer Mark Zuckerberg on Wednesday said protecting a democracy is an arms race, and both the public and private sectors must combine to counter outside interference. Writing in The Washington Post, Zuckerberg acknowledged his company had been late in discovering that foreign actors were running coordinated campaigns to interfere with the 2016 United States presidential elections.

His statement comes ahead of a US Senate committee hearing later on Wednesday that will focus on measures taken by social media firms to counter attempts to influence voters. Twitter founder Jack Dorsey and Facebook Chief Operating Officer Sheryl Sandberg will appear before the Senate Intelligence Committee to elaborate on their firms’ actions against Russian government-linked campaigns aimed at influencing voter opinions in the United States.

In his article, the Facebook CEO explained the various initiatives taken by his company to block potential threats. “With advances in artificial intelligence, we now block millions of fake accounts every day as they are being created so they can’t be used to spread spam, false news or inauthentic ads,” Zuckerberg said.

“We look proactively for potentially harmful election-related content,” he wrote, adding that any violations are removed immediately.

Alphabet Inc’s Google has declined the committee’s request to send one of its senior-most executives. Google spokesperson told TechCrunch that it will send its Chief Legal Officer Kent Walker with a written testimony to represent the company. “Walker reports directly to our chief executive officer [Sundar Pichai] and is responsible for our work in this area,” Google’s spokesperson said. “Walker will be in Washington, DC on September 5, where he will deliver written testimony, brief members of Congress on our work, and answer any questions they have.”

Walker released the testimony which outlined measures taken by Google. The statement said Google had taken steps to “identify and remove actors from our products who mislead others regarding their identity, including the Internet Research Agency and other Russian- and Iranian-affiliated entities”. The testimony also said that the search engine had begun a verification ​program for any federal election ads on Google in the United States.

Sandberg also released a statement highlighting her company’s stance ahead of the hearing. “The threat we face is not new,” CNBC quoted Sandberg’s statement as saying. “What is new are the tactics they use. That means it’s going to take everyone – including industry, governments, and experts from civil society – working together to stay ahead.”

Data breach case

Facebook has been under intense scrutiny in the past few months after it became public that British political consulting firm Cambridge Analytica had accessed private information of 87 million users of the social media platform. The company also failed to identify alleged Russian interference in the 2016 presidential election in the United States.

Lawmakers of various countries had asked Zuckerberg to appear before them to explain the data breach. On April 11, he had testified before a committee of the United States Senate in the case.