Port 79 - finger
nmap -n -sV -Pn -p- 192.168.0.102
...
79/tcp open finger Linux fingerd
...
can check if any user is logged on
finger @192.168.0.102
other options
finger root@192.168.0.102
finger szalek@192.168.0.102
finger user@192.168.0.102