Every single piece of closed source software produced, that requires any kind of Login has a set of standard logins that are not made generally available. This is for debugging, fault finding, and they can be put to dubious use. The problem is not that they exist, it is not that they may or may not have a suspicious reason for existing. It is the fact that a disgruntled employee of say M$, a cracker who has learnt the secret accounts, or a malicious person can access your system without you knowing and there is little you can do about it. You have to find those accounts before you can delete them. Under M$ Windows it is easy to hide programs at a system level from anyone with admin. privilages. And if you configure a good firewall you can take your first steps to protecting yourself against this sort of thing.
It only shows another reason why one should use open source software. That is the only way to be secure.
[ March 12, 2003: Message edited by: Linux Frank ]