I was reading a forum posting about a business where users refused to give up their gigantic pst personal archives (a common lament that I've made as well). Many of the comments revolved around taking control and user smack-down. It just made me shake my head and move on to something else. Too bad. I was hoping to find some good information in that conversation.
Experience is a helpful thing to have. I've fought the email battle before: old server, no expansion possible, users constantly over their limits and using their inboxes as file storage. After I got done beating my head against that wall I learned something: Users will use the tools you give them to accomplish their tasks and it may not be in the way you envisioned. It might even be the "wrong" way. It's an evolutionary process and, just like evolution, there's no wrong way if it accomplishes the desired result (and complies with law, regulation, policy, etc, etc).
We IT hotshots come along in the middle of the evolutionary process and scream, "You're all doing it wrong!" But who are we to decide what's wrong? Who among us hasn't lamented the benighted user's decision to use a tool in the most asinine way? And yet those same users get their jobs done and the tool seems to help them.
Efficiency isn't the holy grail we think it is. Nor is conformity. Providing appropriate tools and enabling workers to do their job is far more important. The real purpose of IT is to make things work so the business value increases. Unless IT is the purpose of the business, we're here to do as we're told. We are *not* the enforcers.