AccessLevel controls one thing (which turns out to be not
very important, security-wise).  PrivelegeLevel controls another
thing (which is VERY important, security-wise).

From an account with AccessLevel 9 and PrivelegeLevel 0, you can not do
things that would compromise security (e.g., mess with other users'
files, get a DOS command prompt, use the admin command).  Do not give
your users high PrivelegeLevels unless you really, really trust them.

Repeat:  be careful with PrivelegeLevel.