A patent application, published on June 14 and first reported on by Metro, lays out technology that would use audio in TV ads that people can’t hear, but can turn on their phone’s microphone. It can then record the audio, sending it to Facebook, allowing it help the social media giant target ads to you.

“It is common practice to file patents to prevent aggression from other companies,” Allen Lo, VP and deputy general counsel and head of intellectual property, told Fortune in an emailed statement. “Because of this, patents tend to focus on future-looking technology that is often speculative in nature and could be commercialized by other companies. The technology in this patent has not been included in any of our products, and never will be. As we’ve said before, we often seek patents for technology we never implement, and patent applications should not be taken as an indication of future product plans.”

While Facebook has dealt with a slew of ad meddling issues around the 2016 presidential election, many have also voiced concern about the amount of information Facebook already has on its users (and non-users) and how that data gets used. Facebook has also repeatedly reassured its users that it doesn’t listen to their conversations.

Ultimately, Facebook is a site that doesn’t charge its users, instead getting its money from ads, specifically targeted ads. Being able to better target ads helps Facebook, as does preventing other companies from being able to better target ads.

It’s also worth noting that Facebook filed for the patent back in December 2016, post-2016 presidential election, but pre-Cambridge Analytica scandal.