Default file/folder security permissions for a new user

In windows xp, I do the following:

Create new user (Bob). Remove bob as a member of the Users group (he
now is a member of no group). Go to some folder on my box. e.g. C:
\randomstuff. Check the security of this. Check the effective
permissions of Bob with respect to this folder (to find out what he
can really do). Bob seems to by default be able to do a lot of things
with this folder "by default". He can do:

Traverse Folder / Execute File
List Folder / Read Data
Read Attributes
Read Extended Attributes
Create Folders / Append Data
Create Files / Write Data
Read Permission

How is this? Why does a new user get to do all this stuff to
anywhere on my box?

Thanks
.

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