This is what I actually wrote:
"Isn't NTFS basically the same type of file system as MAC?"
I never said that Mac uses NTFS.
The issue at hand was security. I should have been more specific. I was referring to 'access rights' which can be assigned to each file.
I believe both OS have similar ability to assign access rights.
Yes, and both also feature different levels of user accounts and user privileges. One of OS X's nice points is that by default, you start with limited priveleges, and you have to manually enter a password to gain administrator access. On Windows XP, you're given administrator rights from the start. Being unable to access files only really matters if we're talking about protecting the /Windows directory from spyware- or virus-related tampering.