Well, that was interesting.
Spawned into a Mirror Deathmatch game on Blizzard World map, and as is my wont to do I started popping balloons. Working my way through the map, I noticed something was wrong: I wasn't getting killed. I wasn't even getting shot at. In fact, no one was shooting at all except for me. If it weren't for someone out there occasionally using a voice taunt, you could've sworn the map was deserted.
A couple minutes into the match, the game swaps everyone into Doomfist so I elect to take a knee, because popping balloons with Doomfist isn't fun; his spread shot means it's over too quickly and then you're left with nothing to do except wait out the clock. I keep hearing that taunting voice coming from somewhere, but rather than seek out my "opponents" I hit the P button to get a look at who I'm "facing."
It's a full house all right, and what an array of players it is. Five or six of them are rocking the same player icon, so almost certainly a stack, but they're all in on it of course; they'd have to be for no one to be killing anyone. And all of the players without private accounts are very high SR players, diamond at least and even masters; the highest one I can remember was around ~4200.
When my time as Doomfist was over, I resumed popping balloons. Didn't look for them, didn't use map chat, didn't deviate from my routine at all. The final character swap was to Widowmaker, and as I finished with the balloons and moved on to the condiments and drinks, I kept hearing one of them spamming the "A single death..." voice taunt. But the clock wound down, the match ended, and it was over with zero kills for everyone.
Play of the game was me, taking a knee as Doomfist. :O