https://thenextweb.com/facebook/2018/06/29/facebook-wants-to-listen-to-you-watch-its-ads/

A patent from Facebook came to light earlier this week, depicting technology that Facebook would use to quietly activate a user’s microphone in order to listen to them as they watch ads. How hard can I “nope” out of that?

The details: The patent, filed earlier this month, was originally discovered by Metro. It describes a process by which secret messages embedded in TV ads, inaudible to the human ear, would trigger your smart device to record you while the ad was playing. It would then send the audio to Facebook, in order for it to hear your reaction to the ad. You can view the patent here, complete with stick-figure ballerina.