Stephen Shankland/CNET

Mozilla, the nonprofit behind the Firefox web browser, has launched a petition to try to pressure Facebook into making its app more private.

"Mozilla is asking Facebook to change its app permissions and ensure users' privacy is protected by default. And we're asking users to stand with us by signing our petition," said Mozilla privacy advocate Ashley Boyd in a blog post Tuesday.

Detailing her request, she said: "Facebook's current app permissions leave billions of its users vulnerable without knowing it. If you play games, read news or take quizzes on Facebook, chances are you are doing those activities through third-party apps and not through Facebook itself. The default permissions that Facebook gives to those third parties currently include data from your education and work, current city and posts on your timeline."

The petition is the latest pressure on Facebook in the wake of revelations about how Cambridge Analytica was reportedly able to siphon data about millions of us on Facebook then feed that profile information into US and UK political campaigns. So far the situation has triggered multiple government investigations, the suspension of Cambridge Analytica Chief Executive Alexander Nix, calls for Facebook CEO Mark Zuckerberg to testify before Congress, and a viral push to quit Facebook.

Facebook didn't respond to a request for comment.