Replacing tar

It is late, and I am at a loss. I have been having difficuties with dselect, but when I run ==debug, it usually works so I do not know what the problem is. I have tried un-tarring a file, and I get absolutely nothing. I have downloaded another tar.deb file, but I keep getting the same error (

Linux security

I was having a discussion with my ISP about Linux. He said he uses Windows NT because it is much more secure than Linux. He stated that since the source code was available that it was very unsecure. He mentioned something about attaining root access by downloading /etc/passwd and de-crypting