The IP address that you see from finger or who is the IP of logged user.
Use the "last" command to see users previously logged or still logged in.
You can retrieve the information about users like :
example : you run "finger" and you see user "ssh" logged in, then you can "grep ssh /etc/passwd" and you should see :
- the part "Privilege-separated SSH" is comment, and usually this is additional information about certain user.