The encrypted messaging service — a non-profit that rivals Facebook-owned WhatsApp — said in a blog on Tuesday that Facebook had blocked one of its ad campaigns on Instagram, which is owned by Facebook.
"We created a multi-variant targeted ad designed to show you the personal data that Facebook collects about you and sells access to," Signal wrote.
Signal said that Facebook "wasn't into that idea" and claimed that its ad account had been disabled as a result.
Facebook described the ad campaign as a stunt and claimed that Signal had never actually tried to run the Instagram campaign.
"This is a stunt by Signal, who never even tried to actually run these ads — and we didn't shut down their ad account for trying to do so," a Facebook spokesperson told CNBC on Thursday.
"The ads were rejected, and Facebook disabled our ad account.
"The biggest threat to Facebook is a non-profit funded by WhatsApp founders," he said