We had a user that left the organization; in deleting the user from the organization, they didn't get removed from all boards (the wrong option was selected when deleting them at the time). Now that user is still lingering in the system on some cards and I didn't see an obvious way to remove them other than manually removing each instance of the user. Is there an easier way to mass-remove the user when their profile no longer shows up under the organization?
You can remove the user from each board that they are on; that will remove them from all cards on the board. There is not (currently) an easier way to do this.