"The developer threatened to kill Gabe Newell
This is the first and only example—at least I hope—but worth noting to round out the list. As a general rule: don't ever threaten to kill anyone, ever. And not just because it may get your game removed from Steam. Because, like, it's a criminal act and a shitty thing to do.
Paranautical Activity was taken off Steam in October of 2014 after a member of the development team made death threats to Gabe Newell. The developer responsible resigned, then rejoined the studio, then sold the rights to another distribution company, and the game re-arrived on Steam".