This is the result of the finger
command (Today(Monday) when I (Vidya) logged in)
sekic1083 [6:14am] [/home/vidya] -> finger
Name Tty
I had the same question as you but I wanted to kill the gnome terminal which I was in. I read the manual on "who" and found that you can list all of the sessions logged into your computer with the '-a' option and then the '-l' option prints the system login processes.
who -la
You should get something like this. Then all you have to do is kill the process with the 'kill' command.
kill