Is your phone secretly listening to you? Here's a simple way to find out

If you're a smartphone owner--and chances are that's everyone reading this--you've probably encountered an eerie, but all too common scenario: One day you're talking about a random topic while your phone is next to you and the following day you notice ads start popping up related to that same topic. How do these ads know what you were talking about? Your smartphone may be the culprit. Every smartphone has its built-in microphone constantly turned on in order for the virtual assistant to hear your voice commands. So, could it be that these devices are also secretly eavesdropping on your conversations in order to serve you ads? Here's everything you need to know, plus a simple test to find out.