Although Mark Zuckerberg is testifying before US Congress to answer questions about the Cambridge Analytica scandal and Russian election interference, he also found himself addressing a conspiracy theory that has been around for years: does Facebook secretly record people using a device's microphone for ad targeting purposes?

"Yes or no," asked Sen. Gary Peters. "Does Facebook use audio obtained from mobile devices to enrich personal information about users?"

"No. Let me be clear on this: You're talking about this conspiracy theory that gets passed around that we listen to what's going on on your microphone and use that for ads," Zuckerberg replied. "We don't do that." The CEO added that Facebook could only record audio as part of a video that's being filmed and uploaded by users.

For many years, some Facebook users claim to have seen ads on the platform related to their recent conversations, leading to the suspicion that the company is surreptitiously listening in on them using a device's mic. While there are plenty of advertisements on Facebook, conspiracy theorists say these particular ones feature the same obscure, specific products they were just discussing.

Last October, Facebook's president of ads, Rob Goldman, denied the spying allegations. "I run ads product at Facebook. We don't - and have never - used your microphone for ads. Just not true," he tweeted. Even Snopes has debunked the theory, and the Wall Street Journal posted a video last month explaining why people believe it happens.

As we've been finding out recently, Facebook already knows plenty about its users without having to resort to tactics that could send its employees to jail---and all just to improve its targeted advertising. There are also the technical issues that would make such a practice almost impossible. Facebook may be a privacy nightmare, but it definitely doesn't record your conversations.