Since tables are regular UNIX files, I have so far found no need to implement, and have the associated overhead of, general data access controls in NoSQL. Setting the UNIX permissions on files or directories has proven very useful and effective. This is another example of how the NoSQL system works "with" UNIX, not in addition to it, e.g., not duplicating UNIX functions. So, for those who say that NoSQL isn't a multi-user DBMS, I'd reply that it is as multi-user as the underlying filesystem allows it to be.