We are all mad online sometimes, and the more we protest that we are not mad, the madder we surely are. And so modder Eric, who runs the Youtube channel Insert Controller Here, has built a controller for all of us. When you get so salty that you can't stand another second of your stupid team in Overwatch or that stupid sniper who keeps shooting you in the head, you can literally pour some salt into a glass of water to quit the game. This is how mechanical engineers write poetry.
The video above shows off this work of art, though I also recommend the build video, which shows how he put the whole thing together. The trick is that adding salt to the water lowers its electrical resistance (making it a better conductor), which can be detected by a couple of screws in the glass attached via wire to an Arduino microcontroller. When a change in resistance is detected, the microcontroller sends a command via USB and rage quits on the spot.
Eric unfortunately doesn't show off the code required to make the Arduino pull off this command, but it's fairly simple programming, and he listed some of the basic functions on his website. Each game will of course need its own unique command, but that should be easy to adapt to pretty much anything on PC. So far he has it working with Overwatch, League of Legends, and Smash Bros. on the Switch.
Really, if there's any flaw in the version in the video above, it's that it bothers to go through the menu to quit a match. Real rage quitters just ALT-F4.