Facebook CEO Mark Zuckerbergahead of two congressional hearings this week. Zuckerberg faces mounting criticism after private information from as many as 87 million Facebook users was .
Facebook will begin notifying affected users Monday. Meanwhile, there is major financial fallout from the data leak. Facebook stock is down nearly 15 percent since the Cambridge Analytica story broke. That's a drop in market value worth tens of billions of dollars.
Last year virtually all – 98 percent – of Facebook's revenue came from advertisements. Some companies have begun pulling millions in ads from the platform.
Mozilla, the maker of Firefox, was the first company to pull its ads following this data controversy, reports CBS News correspondent Tony Dokoupil. While it's only a sliver of Facebook's revenue, Mozilla is also spreading a message about privacy rights online – a message that could cost Facebook dearly.
For years Mozilla used Facebook to tell people about its products, but now the nonprofit has a new message. It's pulled all advertising off the social network – indefinitely.
"Trust, right now, isn't being earned. I mean, technology companies aren't treating people like people. They're not treating people like human beings. They're expecting them to have an unreasonable amount of knowledge about how their information is being used," Mozilla chief marketing officer Jascha Kaykas-Wolff said.
"We're uncomfortable with the way that technology companies are treating people. Like, fundamentally. Absolutely, businesses should be able to run using data. … But technology companies can't take for granted that all the things that they're doing are easy to understand," Kaykas-Wolff added.
Kaykas-Wolff showed us just how Facebook tracks and uses your data.
"We choose to click on this ad. When we click on this ad, something happens. The data that's been associated with my profile in this social media site is turned into a cookie. The data… actually follows me around to every next website that I go to," Kaykas-Wolff explained. "If we've had an experience where maybe we've chosen to buy something or been thinking about it and an ad shows up on another site… you see an ad specifically for those pair of shoes. It is a little bit like you're carrying some baggage."
"It seems to me like Facebook puts a little bug on you," Dokoupil said. "They're following you."
"A bug or baggage – really same basic idea," Kaykas-Wolff said.
David Polgar, a tech ethicist, said "no social media platform is free" and we are paying with our personal data.
"Your privacy is a currency. Every time you log onto Facebook or any social media platform you are giving currency, you're just not giving dollars," Polgar said.
Like Mozilla, the home sound company Sonos also stepped back from social media platforms and took a week-long pause from advertising on Google, Twitter, YouTube and Facebook.
"We thought a week would be enough… for us to take a pause and take stock of what we could do, to be more – a more positive agent for change in the tech ecosystem," Sonos chief marketing officer Joy Howard said.
Facebook and Instagram have been a vital tool in Sonos' success as a company.
"Companies are as dependent on these platforms as human beings are dependent on these platforms. … And there is no opting out of them, especially when we're in a world in which Facebook and Google are a duopoly over all ad and media spending," Howard said. "But ultimately, the platforms are only as useful to us as they are to customers. And so when people start to lose trust in the-- in these platforms, then their business value to us diminishes."
In an interview with Bloomberg, Facebook COO Sheryl Sandberg addressed that breach of trust with advertisers.
"Advertisers are people. They're people who use Facebook, so are investors. And everyone wants to know the same thing, which is: are you protecting people's data?" Sandberg said.
As for how Facebook has responded to criticism, Kaykas-Wolff said he's encouraged that the social media platform is talking about re-developing trust with consumers.
"But words are just that. We need to see action. And when product change has happened, we'll know that the message is loud and clear," Kaykas-Wolff said.
More than a quarter million people have downloaded Mozilla's new browser add-on called Facebook container, which prevents Facebook from tracking what sites you visit outside of its platform. Facebook tells us it is working with advertisers to improve the controls people have on Facebook and the transparency around the ads on the site.