I'm Carla Zeus for seeing that 10.

And this Friday we're presenting the third installment of our fourth part.

Special Report on Facebook.

The company, whose monthly users include 1/4 of the global population, has become a networking tool many of them can't live without and made mistakes.

Many can't forgive the Nation of Russia factors in today.

It has repeatedly denied interfering and international affairs like the 2016 U.

S.

Presidential election.

But the world's biggest social media company started noticing suspicious activity on its platform activity it says was connected to Russian operatives, and how Facebook reacted dramatically damaged the trust its users had in it.

Once again, Laurie Seagal has our in depth report, and meanwhile, CNN dot com is featuring breaking news and other stories from around the world.

It was 2016 and politicians had realized the reach of Facebook.

Today you wrote a Facebook post.

The platform was integral to politics and had been for years.

I'm the guy who got Mark toe wear a jacket and time, but unnoticed with all that hype.

New details about the extent of Facebook's role in Russia's election interference campaign in 2016.

A campaign on Facebook to disrupt the U.

S election and divide America was well under way way.

Meet Alex Stamos.

Good.

He's a respected figure and security.

Let's survive the last day.

Today is August 17th 2018.

Tough to say goodbye to folks, but I'm glad for what comes afterwards.

It's the last day he'll call himself chief security officer of Facebook.

He's been there three years.

You.

It feels weird to live through history from the inside.

I think naturally, I wantto question whether I did everything I could.

It was stainless, his team who discovered Russians were weaponizing Facebook to influence the election.

Ah, pivotal moment for democracy and a turning point in Facebook history.

It started the spring and summer of 2016.

The race for president was in full gear.

Facebook security team discovered suspicious activity connected to Russian intelligence and reported their findings to US law enforcement.

Why was Facebook not transparent?

As people went to vote, you know, in in the fall it just wasn't seen as our position to kind of get involved publicly in these these massive political issues.

And in this situation, you know, you do not want to be seen as putting your thumb on the scale one way or the other.

At the time, Zuckerberg downplayed the idea that fake news on Facebook, of which you know it's a It's a very small amount of, of, of the content influenced the election in any way.

I think is a pretty crazy idea.

I just think at the time I was way too dismissive.

I think I just reacted and had had a negative, visceral reaction to the idea that people were somehow tricked.

By January 2017 U S intelligence report linked the spread of hyper partisan fake news to the Internet Research Agency, a Russian company with close ties to Putin and Russian intelligence.

Their entire goal was to reduce the quality of discourse and to increase anger and divisiveness in the country.

The Russians took advantage of Facebook's advertising tools, which allow advertisers to target people specifically based on their interests, even their political biases.

On top of that, the more polarizing and divisive their post war.

More likely, Facebook's algorithms would show them to more people.

Publicly, the company was limited in its transparency.

There be even more revelations later, internally Facebook execs treated the foreign interference like the shift to mobile all hands on deck and started to increase its security team by 2018 it would be more than 30,000.

But Facebook's failure to anticipate and quickly address foreign government influence on the platform put the company on thin ice.

Facebook, battling a massive data on this new scandal thin straw that broke the camel's back would come early.

2018.

Millions of users had their information improperly obtained by a data firm.

Data firm Cambridge Analytica harvested data from Facebook users data of up to 87 million Facebook users to be precise, collected before the election.

The way they got the data was simple.

Through a personality quiz app taken by about 300,000 Facebook users.

What few of us knew was taking.

The quiz gave the researcher access to not only our data but also our friend's data.

This methodology was completely permissible at the time.

Up until Facebook restricted access in 2015 looser privacy settings allowed developers more access to our information thes air ethical debates that will impact two billion people about user data about the spread of fake news about the weaponization of the platform.

People were outraged.

You have users asking, Should I be spending so much time on Facebook?

Maybe I should delete it.

It all dated back to when Facebook opened up the platform to developers.

I think they built something that was beyond their wildest dreams.

And it was extremely powerful in ways that they had no idea it could be powerful.

Did you think?

Oh, no.

Because this is, you know, this was based off of the platform that you weren't early architect of.

Yes, is the answer.

I don't think it was something that you could have predicted or even thought was.

A risk.

Social media powerhouse has been reeling, seeing its worst day in four years.

It was a turning point for the company user.

Trust eroded and Facebook stock price plunged and the anger on Lee amplified as days went by and there was silence from the upper ranks until Mark finally decided to talk.

Senior Tech correspondent Laurie Seagal got this exclusive interview to meet what happened.

What went wrong?

This was a major breach of trust, and and I'm really sorry that this happened.

They were previous instances where they had the issue.

Apologies for breaches.

In the past, this was different.

Senator John Thune and much of Washington was watching closely.

Everybody wants you to show up.

Um, will you testify before Congress?

I'm happy to.

If it's the right thing to do, You are the brand of Facebook.

You're the name of Facebook.

People want to hear from you.

We just want to make sure that we send whoever is best informed of doing that.

Zuckerberg agreed to testify on April 10th 2018 and the prep started inside Facebook.

They built a mock hearing room.

He worked really hard to prepare and he was ready.

I mean, that was as high stakes as it gets.

Facebook CEO Mark Zuckerberg, just hours away from testifying It felt historic the way it was for the tobacco execs in 1994 Remembers someone that day, told me they had to bring in an extra row of chairs for the senator's because there was so much interest.

We're listening America's listening and quite possibly the world is listening to and wondering.

Could Zucker Burg, who historically has had a hard time with high pressure public moments, deliver We didn't take a broad enough view of our responsibility, and that was a big mistake.

And it was my mistake.

And I'm sorry I started Facebook.

I run it and I'm responsible for what happens here.

His performance in front of Congress.

Waas poised We had the right answers.

I think he did laps around the people there.

But part of that success was due to the fact that many of the questions asked by the senators demonstrated a lack of understanding about how Facebook and Tech and general works.

If I mean, if I'm feeling emailing within WhatsApp, does that ever inform your advertisers?

How do you sustain a business model in which users don't pay for your service?

Senator, We run ads, I say.

It was an embarrassment to the members of Congress, it reconfirmed, but most of the Valley and frankly, probably many of the viewers thought was that most of these men and women don't even understand the basic business model, let alone the amount of data that's being collected.

In the nature of these new communities, there's going to be a different approach taken in the future approach many thought would be regulation.

But after two days of testimony.

What kind was unclear.

You don't wantto put a heavy burden on the goose that laid the golden egg.

Social media is not going away.

Technology is not going away.

I would hope they would work with us on.

Facebook would try to get in front of impending regulation by promising to give users more control over their data and by investigating tens of thousands of other APS that were allowed to collect user data.

But it still came down toe.

One fundamental question.

Did making money get in the way of Facebook's mission toe ultimately connect the world?