This one fact is (in my mind) the death-knell of this whole misguided idea. Also note that once you set up the case sensitivity status on a directory/device, i

This one fact is (in my mind) the death-knell of this whole misguided idea. Also note that once you set up the case sensitivity status on a directory/device, it could be hard to change it. For instance, if I have two files named "I.txt" and "i.txt" in a directory that is case-sensitive, I can't change that directory to case-insensitive using English rules. But I could using Turkish rules. You would have to do a full scan of the area you are planning to change in order to check whether anything would clash. Also, you have the problem of filename searches. At the moment, it is possible to open a file by name in a directory that has lots of files, and the filesystem can do an indexed search for that file. If you change it to case-sensitive, then either you need to do a linear search instead (which could absolutely cripple some use-cases), or store an indexed case-insensitive lookup table, with the additional proviso that the index must be able to give you back the canonical filename. If the case-sensitivity changes, then this index must be recreated from scratch.