A website hosts private/personal information at a very long and unpredictable URI, yet access to this URI is completely unauthenticated. Are there any major security issues with this?
I can think of some straight away:
- Search engines might index the information if the link ever appears anywhere on the web
 - It would be trivial to access the information by simply looking at someone's screen and remembering/taking a photo of the URI
 - Alike to the above, the data would also be very accessible from the user's browsing history
 - Depending on various factors, the URI might be brute-forced eventually
 
Are there any others?