If a hidden Twitter window decides to load and invisibly auto-play a video, your screen will never auto-lock. Proof:
% pmset -g assertions | grep PreventUserIdleDisplaySleep
pid 492(Twitter): [0x0002b542000525f7] 02:09:55 PreventUserIdleDisplaySleep named: "com.
apple. avkit. disableUserIdleDisplaySleep"
But at least this idiotic slow-clap is in good company, since playing HDMI audio in iTunes does the same fucking thing.