AKIPRESS.COM - Facebook CEO Mark Zuckerberg was pelted with tough questions on the company's data collection practices and the need for new regulation during a five-hour hearing with the House Energy and Commerce Committee on Wednesday.

It was his second and final hearing this week in the wake of the Cambridge Analytica data scandal, bringing the once press shy CEO's total time testifying on Capitol Hill to about ten hours, CNN reported.

Zuckerberg repeated an apology offered in the previous hearing that Facebook made a "big mistake" by not taking "a broad enough view" of its responsibility.

But he faltered somewhat Wednesday when pressed by Rep. Frank Pallone, a Democrat from New Jersey, for a "yes" or "no" answer on whether Facebook would commit to changing its default settings to minimize data collection "to the greatest extent possible."

"This is a complex issue that deserves more than a one word answer," Zuckerberg said. Pallone called the response "disappointing."

The Facebook CEO has said before that his industry probably needs to be regulated. He repeated that in response to questions Wednesday.

"The internet is growing in importance around the world ... I think it is inevitable that there will need to be some regulation," he said.

However, when asked whether he would support specific proposed privacy legislation, like the Browser Act, Zuckerberg hedged and cited what he said was his lack of familiarity with the details.

In both hearings, legislators pushed Zuckerberg on its potential monopoly power. Zuckerberg said Wednesady that Facebook feels "a lot of competition" because the average American uses eight apps daily to stayed connected to people. It's unclear, however, how many of those apps are also owned by Facebook.

The data scandal wiped away tens of billions of dollars from Facebook's market value, prompted political scrutiny on both sides of the Atlantic and even raised the once unthinkable question of whether Zuckerberg should step down as CEO. It also reignited long simmering concerns about Facebook's impact on the world's privacy, civil discourse and domestic institutions.

Investors appeared to like Zuckerberg's debut on Capitol Hill. Facebook stock ended Tuesday up 4.5%, and ticked up another 1.5% in trading Wednesday.