Well it seems you'd have to not only guess the file name, but also the 5 character code; as it appears its uppercase, lower and numbers, which is ~916 million p

Well it seems you'd have to not only guess the file name, but also the 5 character code; as it appears its uppercase, lower and numbers, which is ~916 million possibilities ...although on second thought, and with some bad math, if you know the file name, and you can manage 750+ tries a second, you could brute it prior to the 14 day expiration.