There’s no denying that Facebook knows a ton about you. But just how much of your info does it have, and how does the company go about getting it? The social media giant closely follows your activity both on the web and in real life in order to target advertising at you—but some users think it goes further than that. There’s even a popular theory that the site may be listening in on your conversations.

One user told Mashable that he tested the hypothesis by talking about Kit-Kat candy bars constantly for two days. After that, he claims Kit-Kat ads began to appear on his Facebook. Another user recounted a similar episode when she texted a friend about Warby Parker glasses, and then began to see ads for the company pop up in her feed.

However, the microphone listening theory has been denied by Facebook. So what’s the explanation for strange incidents like this? Basically, we forget all of our online behavior that Facebook is capable of observing, and chalk up any weirdness to spying because we already suspect the worst from Facebook. And that’s not necessarily wrong.

“In many ways, of course Facebook is spying on you,” said Brandie Nonnecke, an IT expert at the University of California Berkeley. “It’s not doing it for malicious reasons. It’s trying to tailor content to you and advertisers.”

So while that isn’t exactly comforting, at least Facebook isn’t physically listening to you. We don’t think, anyway.