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Mozilla’s latest edition of *Privacy Not Included reveals that creepy data collection and sharing remain common on Facebook Messenger, WeChat, and other popular apps

Mozilla is also urging Slack to introduce a ‘block’ feature to mitigate harassment

(SAN FRANCISCO, CA | September 21, 2021)
-- In a review of the privacy features of 21 popular video call apps, Mozilla only singled out two for outstanding features (Signal and Threema). Meanwhile, three products were slapped with a dreaded “*Privacy Not Included” warning label (Facebook Messenger, WeChat, and Houseparty).

Mozilla’s research also reveals that Slack, one of the most popular chat products, doesn’t give users the option to block contacts — a design decision that can enable harassment. As a result, Mozilla has launched a petition urging Slack to add a “block” functionality.

The research is the latest installment of *Privacy Not Included, Mozilla’s privacy-centric consumer tech guide. As the world grapples with the Delta variant, and as the business and education worlds navigate hybrid environments, *Privacy Not Included helps consumers choose products that respect their privacy and security — and avoid products that don’t.


In this edition, Mozilla researchers revist the original 15 apps we reviewed in the spring 2020 guide to see which are improving and which are backsliding. Mozilla also researched six new apps and answered important questions for consumers, like What data does the product collect? Does the product use encryption? and How does the product use AI?

Says Jen Caltrider, *Privacy Not Included Lead at Mozilla: “Video call apps are now a routine part of millions of people’s lives. And even when the pandemic recedes, that won’t change. In this new world, people deserve to know if the apps they’re using everyday respect their privacy — or if they’re snooping on them.”

Caltrider continues: “While video call apps may feel more intimate than social media platforms, there’s still a ton of data being collected, stored, and shared. For that reason, users should assume that anything they say on a video call app could be made public.”

People deserve to know if the apps they’re using everyday respect their privacy — or if they’re snooping on them.

Jen Caltrider, Mozilla

Top findings include:

Privacy is a luxury. Only two apps earned Mozilla’s “Best Of” designation: Signal and Threema. Signal is free, but Threema costs $2.99. Meanwhile, three apps earned our “*Privacy Not Included” warning labels, including WeChat, Houseparty, and Facebook Messenger (all are free). These apps use poor encryption, or else collect large amounts of personal data and then potentially share it with shady data brokers

There’s no good solution for harassment. Workers or students facing harassment on video call apps often lack in-product support. Slack has no way to block a user, for example, and while Teams has a block feature, it’s only for personal instances, not for school or work instances. Forcing people to rely on HR or IT departments to protect them from abuse over messaging platforms is not ideal. To help address this problem, Mozilla has launched a petition urging Slack to introduce a “block” feature

Apps’ privacy policies are basically unreadable. We learned just 8 out of 21 products have user-friendly privacy information available to consumers. Finding out data retention periods and how to delete data is especially challenging. Further, big companies like Microsoft tend to use a general umbrella privacy policy, so it’s difficult to know specifically what personal data a video call app collects

The pandemic is forcing some apps to improve. Many apps weren’t ready for the rapid growth sparked by the pandemic, but have since improved. Several apps have added great new features, like more end-to-end encryption (Zoom), strong password requirements (Discord and, and more, as well as many new user experience features, like smart AI assistants and AI-driven noise reduction




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