It's not often that anyone can say it's been a brutal week for Facebook CEO Mark Zuckerberg.
But today, his social-media company's share price took another beating after businessman Elon Musk deleted the Facebook pages of Tesla and SpaceX.
Each had more than 2.5 million followers.
Facebook shares fell 3.34 percent to close at US$159.39.
They stock traded at $176.83 at the start of the week—meaning the share price has dropped 13.89 percent since Monday.
However, it's still up 13.57 percent over the past 12 months. Facebook's market value is now $463 billion.
A "delete Facebook" movement started after it was revealed that a U.K.-based company, Cambridge Analytica, gained access to data on more than 50 million Facebook users.
Cambridge Analytica made this information available to Donald Trump's presidential campaign and those advocating that Britain end its membership in the European Union.
The former research director with Cambridge Analytica, former British Columbia resident Christopher Wylie, blew the whistle on this in a series of media interviews.
That has prompted investigations by Canada's privacy commissioner and the U.K.'s information commissioner.
Victoria mayor also pulls the plug
Victoria mayor Lisa Helps also deleted her Facebook account this week.
She called the social-media platform a "toxic echo chamber" and a place where "people who have anything positive to say are often in defense against negativity and anger".
"Facebook peddles in outrage," Helps wrote on her blog. "According to Roger McNamee, an early investor in Facebook, 'Algorithms that maximize attention give an advantage to negative messages. People tend to react more to inputs that land low on the brainstem. Fear and anger produce a lot more engagement and sharing than joy.' "
She also declared that social-media companies are competing for people's attention, which keeps people distracted.
"This is contributing to fragmenting our attention spans so that we no longer have the ability to focus individually or collectively on the big issues that desperately need our attention," Helps stated. "This isn’t good for the state of our democracy in Victoria where what we need is to be able to talk with each other and listen to each other about the challenges we face as a community."
But she admitted that it wasn't easy.
"Over the past few weeks, I’ve been weaning myself off Facebook slowly, just like when I quit coffee," she wrote. "I first deleted the Facebook app from my phone. Then from my iPad. And finally, I changed my web browser home page. The final step is to close down my Facebook account … It makes me nervous just typing this."More