Security Question

I have an old ‘my book live’ which I used with a Windows 7 laptop. I have recently been converted to Linux os on my laptop and decided to try and connect ‘my book live’. Much to my surprise I appear to have full unrestricted access to all files by simply logging on as “anonymous” which appears to bypass any user name or passwords which had been previously set up. This only goes to show how good Linux is at accessing connected resources, but leads to to ask the question, is this a vulnerability issue, leaving all data open for any would be Linux based hackers?

If anyone has any experience of this, I would like to find out more, thanks