Only once did I see emacs malloc all of my ram, but it did it on the server and crashed it. No clue what happened, but I barely got top open to see it happen before the kernel panicked.

A once-in-a-lifetime experience though, I start the emacs server on boot so I can start clients much faster, which means it's always running as long as my computer is on, and it's never had any issues other than that one time.