How do I find people on the Internet?
finger
finger is a program that displays information about users on a particular system.
finger can be used two ways:
use the finger command to ask for information about a particular user. To do this, you need to provide the name of the machine that the person uses.
to find out who else is currently logged on to the same machine that you are logged on to.
In order for this to work, finger must be running on the remote machine (i.e., the
machine used by the person you're interested in locating).