I have been a member of the Association of Computing Machinery (ACM) for a couple years, but I am letting the membership lapse as there is much less connection to my current work - though not my interests. One of things I will miss is the monthly Communications of the ACM and things like Phillip G. Armour's "The business of software" column. His Oct 2009 entry, Contagious craziness, spreading sanity, is no different. (Sadly, full text only available by subscription.)
What he discusses is the nature of people in groups. There are people (often leaders of some sort) whose behavior sets the tone for the whole group. If no one questions "odd" behavior, then the group somehow develops a mental tick that makes the "odd" behavior acceptable. Similarly, as soon as the behavior is questioned, then others in the group suddenly realize that they can push back on the behavior. As I write this, I am reminded of the Abilene Paradox.
I loved Armour's take on Newton's first laws as applied to behavior: "Every behavior will continue until acted upon by another behavior."
Armour also does a nice job of making this real with some examples and reality checks. If you never say "no" to a pile driver of a boss / customer, then they will keep asking you for more.
[Photo: "February 10th 2008 - This might be contagious" by Stephen Poff.]