ACLs are, for the most part, unneeded.<p>The old (other, group, user) * (read, write, execute) unix model is much easier to use, and sufficient for the vast majority of uses.<p>Occasionally, there is a need for something that can be expressed by ACLs, but not by Unix permissions. In most deployments, it is so rare that people who are not aware with ACLs just find some other way to do it.<p>ACLs are not the end-all-be-all permission system either. I would really like a permission system that says &quot;in this directory, everyone can create a file, but no one can create an .mp4 or .mp3 or executable file&quot;. ACLs can&#x27;t do that.<p>Some 20 years ago, when I occasionally had to audit file system permissions, Unix ones were usually properly set up (every user has write access to their own stuff, read access to shared stuff, and no access to other&#x27;s users stuff, with groups used to do exceptions), and NT systems were always a mess, with lots of unexpected permissions and wrongly set up ACLs because complexity.<p>The best setups were always Novell Netware with their &quot;Trustee&quot; security model, which makes it much easier to get what you want than either ACLs or Unix perms