Facebook founder and CEO Mark Zuckerberg has reportedly faced intense preparation for the back-to-back hearings on the privacy data scandal.
Prior to that testimony, Zuckerberg visited Capitol Hill to meet with Florida Senator Bill Nelson, the top Democrat on the Commerce Committee.
Nelson told reporters that he was "highly skeptical" of Facebook's ability to address rampant privacy issues.
"I think he thinks he's taking action, and has in the past. But, I think there's going to be a lot more action he's going to have to take in the future," said Nelson.
"If we don't rein this in, none of us are going to have any privacy anymore," he added. "I think we have just seen one of the openings in the door to taking our away our privacy.”
Zuckerberg will testify before a joint session of the Senate Judiciary and Commerce Committees Tuesday, and then on Wednesday, he'll appear before the House Energy and Commerce Committee, where he is expected to face similar questions.
In a public relations push, Facebook released Zuckerberg's opening statement on Monday.
In it Zuckerberg takes responsibility for his company.
He states, "Facebook is an idealistic and optimistic company. For most of our existence, we focused on all the good that connecting people can bring."
Zuckerberg lays out his version of what happened in the Cambridge Analytical scandal, and Facebook's steps to remedy the events.
He went on to say, "It's clear now - that we didn't do enough to prevent these tools from being used for harm as well. That goes for fake news, foreign interference in elections, and hate speech, as well as developers and data privacy."
Louisiana Republican Sen. John Kennedy says he's concerned Facebook may be too big to fix.
Kennedy said, "Is it fair for me to give up all my personal data to Facebook, and apparently everybody else in Western Hemisphere, in exchange for me being able to see what my high school buddy's had for dinner Saturday night. Who owns my data, do I own it? Or does Facebook own it?"
So what new regulations could on the horizon?
Technology evangelist Brain Vecci with Varonis Systems says lawmakers could take a page from Europe where a new law aims to provide more protection and control for citizens' personal data.
Vecci says, "If you're going to collect this information, the personal information of an EU citizen you need to treat it with respect, treat it like something valuable. You should only collect what you need and when you don't need it anymore you should delete it."
Over the next few days, all 2.2 billion Facebook users will receive a notice titled "Protecting Your Information" with a link to see what apps were used and what information Facebook shared with those apps.