If you look at DLP as an awareness tool, then you can actually fix these broken processes. Each of these mistakes contains several opportunities for improvement. You can train the user about why certain methods are dangerous. You can tell them about better methods that are available. Most importantly, IT becomes aware of dangerous practices for which they have not provided better alternatives. IT professionals: you think you know how the business runs? Put a DLP in "soft" reporting mode for a few months and you will find out that you don't know.
Soft DLP is DLP focused on training and awareness for all sides (IT and users). It allows exceptions ("if you're sure then click continue to do it anyway") and logs the results so that improvements can be made. It's incremental, non-judgmental and business friendly. Eventually, you can tighten controls. You might discover that with soft-DLP, better alternatives and training you don't need as much enforcement. Turns out DLP is not a tool for controlling users, but a tool for teaching IT about the business. That's what makes it so valuable.
Read more about wide area network in Network World's Wide Area Network section.