# "Once mouse lock is acquired, stop mouse events from being fired to other elements that are not locked (e.g., only fire to locked element)." Only the fullscreen element will get events.

# "User agents may prompt for confirmation before locking, this preference may be saved as a content setting" How to deal with this? What UI do we use? See also, "Repeated escapes of mouse lock can signal user agent to not re-lock the mouse without more specific user intent gesture, e.g. similar to how Chrome suppresses repeated alert() calls"

# "The Mouse Lock API must exit the mouse lock state if the user agent, window, or tab loses focus"

# Clip the mouse so it doesn't leave the locked element with a mouse movement large enough to exceed its bounds. See: