A serious problem which the finger system is not capable of addressing is intelligent divulging of information. All information provided by a finger server is available to anyone who can access that server through a network (often the entire Internet.) The problem here is that reliable authentication of the user querying the information, along with any classification of the availability of finger information, is not performed.
Unfortunately, as the Internet has grown, many newer (commercial) sites have declined to support the finger service, making it difficult to obtain information about users on their computer systems (try finding the username of a friend working for a major computer maker...) I feel strongly that some amount of information about computer users at a site should be made public.
Metafinger faces privacy issues at two different levels :
This refers specifically to privacy within a site, e.g. between users of the same computer system. There are two issues addressed by Metafinger:
This is addressed by requiring user authentication by the HTTP
interface before loading a user's profile. When using the UNIX command
line interface, authentication was done at login time. Private mail
aliases, unless declared in a user's profile, are not understood by Metafinger.
The issue of what items of information, if any, about the current
status of an individual user (where they are logged in, when they
logged in, what they are doing, whether they've read their mail, where
their mail gets forwarded to, etc.) should be publicly available is an
often-debated one. To conform to current standards, I limited the
information supplied by the Metafinger server to that provided by the
traditional UNIX finger server.
What a particular user is actually doing should not be widespread
knowledge. Under Unix, this information is always available to other
users of a computer system, and GNU finger incorporates this
information into the server output. In order to conform, this
capability was removed from the Metafinger server.
Another concern is maintaining certain information private within
a site. The main example of this being information about a local group's
membership.
In order to avoid making this information publicly available over the
network, the expansion of group names into user names is done at the
Metafinger client, not the server. A user at site A is limited to
filtering using the mail aliases defined at site A, even when
finger'ing another site.
Current Status
Privacy of the entire Site
Meta Finger Top Level
wad@media.mit.edu