Kassem Fawaz’s brother was on a videoconference with the microphone muted when he noticed that the microphone light was still on — indicating, inexplicably, that his microphone was being accessed.
Alarmed, he asked Fawaz, an expert in online privacy and an assistant professor of electrical and computer engineering at the University of Wisconsin–Madison, to look into the issue.
Fawaz and graduate student Yucheng Yang investigated whether this “mic-off-light-on” phenomenon was more widespread. They tried out many different videoconferencing applications on major operating systems, including iOS, Android, Windows and Mac, checking to see if the apps still accessed the microphone when it was muted.
“It turns out, in the vast majority of cases, when you mute yourself, these apps do not give up access to the microphone,” says Fawaz. “And that’s a problem. When you’re muted, people don’t expect these apps to collect data.”