In a blog post, Signal described how it generated the ads to show users why they were seeing them, simply by declaring upfront the information that the advertising platform relies on to perform its targeting.

"We created a multi-variant targeted ad designed to show you the personal data that Facebook collects about you and sells access to," said Signal. "The ad would simply display some of the information collected about the viewer which the advertising platform uses. Facebook was not into that idea."

The starkly transparent ads used Signal branding and featured the user's professional role, education, interests, hobbies, location, and relationship status, amongst other personal data points pruned from their interaction with the platform. Unsurprisingly, the ads never made it to Instagram users' feeds and Signal's ad account for the platform was summarily disabled.



"Facebook is more than willing to sell visibility into people's lives, unless it's to tell people about how their data is being used. Being transparent about how ads use people's data is apparently enough to get banned; in Facebook's world, the only acceptable usage is to hide what you're doing from your audience."

In recent months, Signal has enjoyed a surge in account sign-ups following a bungled privacy policy update by rival service WhatsApp, which caused a user exodus from the Facebook-owned platform.

The privacy-focused chat app has also been promoted by prominent Signal users like Tesla CEO Elon Musk and Edward Snowden, which has only added to mainstream interest in the service.