Washington D.C. [USA], April 12: Testifying before the US senators for the second day in the wake of the data breach scandal and alleged foreign interference in elections, Facebook CEO Mark Zuckerberg on Wednesday said that his company had a 200-member counter-terrorism team to deal with objectionable content. In the joint hearing of the members of the US House of Representatives Energy and Commerce Committee at the Capitol Hill here, Zuckerberg was asked questions related to how Facebook was planning to tackle on the opioid crisis, data protection, targeted ad system and curbing of terrorist and malicious activities.

Zuckerberg said, "The team is comprised of 200 people, who are focused on counter-terrorism. The content reviewers also go over flagged information."

"I think we have capacity in 30 languages that we are working on and in addition to that, we have a number of Artificial Intelligence (AI) tools that we are developing like the ones that I mentioned that can proactively go flag the content," he added.

Zuckerberg further noted that the counter-terrorism team had designed systems, which helped to proactively flag terrorist groups' communication, thereby removing their accounts automatically.

It is to be noted that in its blog post last year, Facebook said that its team consisted of academic experts on counter-terrorism, former prosecutors, former law enforcement agents and analysts, and engineers.

The committee members expressed concerns about the company's targeted ad system and how it profited itself from the user's personal data.

Zuckerberg clarified that his company tracked browsing activity to deliver targeted ads, but it did not hold onto the user's data.

"We only store them temporarily and we convert the weblogs into a set of ad interests that you might be interested in those ads, and we put that in the 'download your information' [feature] and you have complete control over that," he said.

Zuckerberg then revealed that his own data was "harvested" among millions of people in regards to the data privacy scandal.

The Facebook CEO further said that his company would verify the identity and location of advertisers, who were running malicious political ads.

Virginia Senator David McKinley grilled the social media mogul over illegal opioid dealers and markets that were using Facebook to promote and distribute drugs, saying that it was "hurting its users".

A member of the committee in the concluding part of the nearly-five hour testimony showed up a copy of the American constitution and offered to give it to Zuckerberg, claiming that Facebook was "anti-conservative in terms of content that is flagged."

Earlier, before the testimony began on Wednesday, the 33-year-old began by apologising to everyone at the Capitol Hill, that he was responsible for the data breach of Facebook users.

"It was my mistake, and I'm sorry. I started Facebook, I run it, and I'm responsible for what happens here," he said.

The hearing took place after reports started pouring last month that the social networking site had compromised with the personal data of over 87 million Facebook users to Britain-based Cambridge Analytica which allegedly influenced voters during the 2016 US presidential election.