A recent client has users who were getting frustrated about the case sensitivity of the UCM logins. Their old system did not have this restriction (feature?) and they wanted this removed. The more of these types of things you remove the less secure the login becomes, but depending on each situation the risk/reward analysis plays to either side of the fence.
This turns out to be a fairly easy task to accomplish. First, the users in question need to be changed to "Global" in the User Admin applet.
NOTE: This means you cannot perform this action with SYSADMIN.
Having switched the appropriate users to Global, you need to add this setting via Admin Server (under General Configuration) or directly to the confing.cfg file. Once added, do not forget to restart the services.