[CC from a thread I made on the Steam Forums]
> It should be obvious what a serious problem this can be from the title alone. I was in matchmaking a few minutes ago, waiting to find a game, and I started hearing someone else through their mic, talking to their roommate(?).
>
> I don’t know how to reproduce it, but I’ll describe what I was doing when it happened. I had just finished a BTB game where—as far as I know—nobody was using voice. After the timer kicked me out back to matchmaking I began hearing the feed from someone else’s mic. I was not in a group anymore, and the UI still showed the “Searching For Players” message. It didn’t go away until after I had been matched up with a group and began loading into the match.
>
> I don’t know if it was someone from the match I had just played, someone from the match I was about to play, or someone I had never interacted with before. It was pretty evident that they didn’t know anyone else could hear them, and that really unsettled me.
I figured I should submit this here as well, being the official support forum.