If you'd like more information to help dispel security myths in your organisation then I suggest you take a look at an extract from the upcoming book "Protect Your Windows Network" which was written by Jesper M. Johansson and Steve Riley. You can download the extracts for free via this link
It's amazing how much of security best practises seem to be common sense and yet many people seem to be unaware of them. Jesper and Steve are well known on the speaker circuit (both regular high scoring presenters at TechEd and ITForum) for their candid entertaining way of stimulating debate in the community. I'm looking forward to seeing the book itself in print as hopefully some of Steve's stimulating graphics will be included as these memorable images do a great job of making the reader think about the real issues.