All in the name of "security"…
Here is a recent little story about when, in the name of "security", a really dumb thing was done, and the response that said a lot about the security posture of those behind the response.
A client of mine has 4 servers (2 for an Active Directory domain, and two for SharePoint/SQL server) hosted with an external provider. I was commissioned to perform a fairly standard install of MOSS 2007 enterprise.
My former life in security still influences me to this day, and thus I always build SharePoint in a fairly locked down fashion. So, apart from some strict naming conventions among components, I used a bunch of user accounts to run the various SharePoint services. I made sure that none of which have any privileges over and above what they absolutely require for SharePoint to work.
The install was fairly flawless and was over in a couple of hours, however my client called me half a day later to let me know that search was broken.
