Every so often we have a client worrying about unauthenticated users. For example, as part of the output of SHOW PROCESSLIST they will see:
+-----+----------------------+--------------------+------+---------+------+-------+------------------+ | Id | User | Host | db | Command | Time | State | Info | +-----+----------------------+--------------------+------+---------+------+-------+------------------+ | 235 | unauthenticated user | 10.10.2.74:53216 | NULL | Connect | NULL | login | NULL | | 236 | unauthenticated user | 10.120.61.10:51721 | NULL | Connect | NULL | login | NULL | | 237 | user | localhost | NULL | Query | 0 | NULL | show processlist | +-----+----------------------+--------------------+------+---------+------+-------+------------------+[Read more...]