Tuc,
Agreed.
It's also important to remember the influence that short-term contractors can have on projects. My first exposure to this was a chap who'd been working for a PT that shared a project with us for 18mths. As such he was exposed to a large amount sensitive information and, perhaps more importantly, was also involved in several anecdotal coffee bar conversations. I was shocked when a week later he turned up contracting for one of the Industrial partners on the same project....