Ever worked with a source control system where you have single user lock on files? This interferes to much with work. You rarely want a locking mechanism in place (that would degrade the ability to work together). I have a nagging feeling that files and folders should not be locked by a single process/applikation. It interferes with many of the things I do. Just look at onenote. Instead of the easy way (locking), the program merges the changes. It's often easier to deal with the edge cases when they arise[...]