A better idea
You can use container files that are formatted as file systems. These can be mounted at each user's login directory. If the container file fills up then that user is SOL without causing problems for others. You can tailor the size of each user's container file to the needs of that user.
This approach has the advantage that it takes a lot less system overhead than using disk quotas. Disk quotas can be used but these "container" files are, I think, more efficient.
Employees don't need a lot of disk space. If they are using a lot of disk space for business purposes then the disk space is not being used properly. Business files should not be kept in employee login directories. All business files should be kept in purpose specific directories outside of the user login area. In other words all accounting files should be kept in an accounting directory tree, all personnel files should be kept in a personnel directory tree, etc. User home directories can then be kept small with either disk quotas or container files. When users find out that they only have a half megabyte of space in their login directory they will not be tempted to download the pornography or games or whatever because there is no "private" place for them to keep these prohibited things.
