Most UNIX-like systems that support ACLs limit the number of ACL entries allowed to some reasonable number. Table 3 shows the limits on Linux.
Table: Maximum Number of Supported ACL Entries File system Max. entries
XFS 25
Ext2, Ext3 32
ReiserFS, JFS 8191
ACLs with a high number of ACL entries tend to become more difficult to manage. More than a handful of ACL entries are usually an indication of bad application design. In most such cases, it makes more sense to make better use of groups instead of bloating ACLs.