I have installed Tails in an USB flashdrive and then booted my macbook with it. I noticed that Tails was capable of seeing my macbook's hard drive. Out of curiosity I tried to browse it.
Interestingly, I was capable to entering /Users/myName and access all files within. Except for a handful of folders: Desktop and Documents. Tails prompted me saying that I didn't have permission for that.
Makes sense: I could very well be a random stranger trying to steal the files out of this computer. But it got me thinking: what exactly is stopping me from accessing such files?
As far as I am concerned, the Desktop and Documents folders or any other file in my macbook's hard drive are not encrypted in any way. I'm no expert, but I doubt there is any sort of encryption protecting such files.
So I guess it is Tails itself. Is Tails deliberately thinking "oh boy this guy could be a random stranger, I better stop him", or is Tails actually trying to access such files but something is stopping it? If that is the case, what is it?
Naturally, the above bears the next question: is it possible to browse/access the files on a computer's hard drive by booting from an OS installed in a flash drive, such as Tails, effectively bypassing any sort of authentication?