Ha... ha?

From my system logs...

• Sep 9 14:04:42 [sshd] Did not receive identification string from [IP snipped]
• Sep 9 14:05:45 [sshd] User root from [IP snipped] not allowed because not listed in AllowUsers
• Sep 9 14:05:54 [sshd] Invalid user fluffy from [IP snipped]

No other usernames were tried. Is this some sort of joke?