Yea, but that was all much later. It wasn't a problem with PWB as it's file system structure, in practice, was /u[0-9]/{projectname}/{username} so when a mount point ran low on space it wasn't the individual user that got hassled, but the projects under the mount. Makes disc usage accounting easy too, if it's under the project, the project pays for it. You can see that structure and how PWB was actually used by a project at http://9grid.org.uk/pwb/users-view.pdf