In the early days of the public Internet, 1993-1994, my job in the "warez" crew I joined was to spend my days grinding through public FTP sites finding folders that had accidentally been left write-enabled and then create hidden folders using escape characters, e.g. ^H^H^H^H that you could only open if you knew they were there. Then my buddies could store all their MEGABYTES of warez in them.