While Mozilla appears to be the first major company to make such a move, many others are currently considering doing the same thing. As The Times reports, the UK's Incorporated Society of British Advertisers (ISBA) has asked Facebook for more answers and will meet with company executives this week. "When we meet with Facebook tomorrow we want to understand the scope of the inquiry Mark Zuckerberg announced yesterday," Phil Smith, director general of ISBA, told the Independent. "We want reassurances for our members that it will get to the bottom of the issues and any implications for the public and for advertisers." The trade body represents over 3,000 brands, including Unilever and P&G, which may consider pulling their hundreds of millions of dollars of ad money from Facebook depending on Facebook executives' responses.

In a statement, ISBA said, "The claims that other apps using the Facebook platform, and predating mid-2015, have collected similar bodies of personal data and that controls for distribution have been inadequate, raise questions about the possibility that Facebook data has been, or is being used improperly elsewhere. ISBA is asking Facebook for a full account of further potential issues so that advertisers can take appropriate measures." The Times reports that sources close to the ISBA have said if Facebook's answers aren't satisfactory, trade body members may choose to pull their ad money. A top UK ad agency also told the Independent that advertisers will start threatening to pull their ads from Facebook if the company can't generate trust in its data security.

Additionally, Nordea, the Nordic region's largest bank, said this week that for now, it won't be purchasing any more Facebook shares. "Given the high-level revelations and the turmoil surrounding the company with a strong public backlash, coupled with the overhanging threat of increasing regulation of the platforms and the EU GDPR on the horizon, we choose to quarantine Facebook," Sasja Beslik, Nordea's head of group sustainable finance, told Reuters.

"We are encouraged that Mark Zuckerberg has promised to improve the privacy settings and make them more protective," Mozilla said yesterday. "When Facebook takes stronger action in how it shares customer data, specifically strengthening its default privacy settings for third party apps, we'll consider returning."