Fork bombing a Linux machine as a non-root user

[M.Rudra]

On Fri, 18 Mar 2005 17:14:48 -0500, Jeff Kinz <jkinz at kinz.org> wrote:
> It is the responsibility of the local sysadmin to set the per user
> resources limits to the level appropriate for local needs.
> To fix this in all versions of BSD/UNIX/Linux even SCOrch:
> Put "ulimit -u <N>" in one of the system wide start up scripts.  this
> will limit each user to a maximum of "N" processes .
> Make N is large enough for each user to run X-windows plus their
> applications. 100 will do it for almost everyone.  Its pretty big
> without being big enough to let a script run away with the system.

Thanks, to all the replies.
So I gather that other users can misuse only if they have physical
access to the said machine ?  If its not a big security threat do i
still need to setup user limits ?  At home its just my 'significant
other', a musician :-) and me. We mostly use it for internet, and
other general stuff.  When not online, we physically disconnect the
wire as a precaution as i cannot lose my case studies and backup.  I
would like to know other better methods to secure my machine.
Thanks, -- 
MR