How can I find out who owns an e-mail address on yahoo.com?

Hi Phuquoc -

1. The easiest - meaning the least complicated - way to get that
information is to write to the email address and ask them who they
are. I state the obvious only because sometimes we tend to overlook
it.

2. You can also join Yahoo (by filling out a profile) and then
searching the Yahoo Member Directory using the Yahoo ID profile. Of
course, if they prefer to keep the information private, it won't be
available to you, but the Yahoo Member Directory page is here:
 - http://members.yahoo.com/

3. After that, I would point you to Yahoo's Privacy Policy. It
unequivocably states that they do not share information with anyone,
although they do comply with subpoenas or court orders, "We respond to
subpoenas, court orders, or legal process, or to establish or exercise
our legal rights or defend against legal claims..."

Or offer proof that the person is engaged in "illegal activities,
suspected fraud, situations involving potential threats to the
physical safety of any person ...", although even then the owner may
not be revealed to you.

See Yahoo's Privacy Policy:
 - http://privacy.yahoo.com/privacy/us/

If there is a very compelling reason to find out who owns that Yahoo
identity, you can try contacting Yahoo on their feedback page, stating
with specificity your reasons for seeking the information. The form is
located at:
 - http://add.yahoo.com/fast/help/us/privacy/cgi_feedback?radio30=radio305

In short, barring the person's telling you who they are, it is
extremely difficult to ascertain who owns an email address on Yahoo.

Search terms used:

  - Yahoo members
  - Yahoo profiles
  - Yahoo privacy

Yahoo guards its users' privacy for the same reason you might wish
your own information to be guarded.

Yours,
Serenata

You can see what info a Yahoo user entered for themselves at
http://profiles.yahoo.com/USERID where USERID is the yahoo account you
are interested in.  You generally don't have to sign in to
Yahoo yourself, unless you start accessing "adult content" restricted
profiles.

  If you have an email from the Yahoo account, examine the full
headers to see if the sender's
true IP address is revealed.  This can provide evidence to confirm any
suspicions you already
have, but if it traces back to a large ISP (like AOL) you'll be back
to the same problem again.
Check any of the public resources on fighting spam for help in
analyzing headers, and for clues
on how to tell if the headers are forged.

  Try a google search for the userid.  People often reveal their
identities in their other activities.
You could also find old headers to analyze.

  As suggested previously, use the legal system.  All of the large
public providers have permanent
staff dedicated to processing legal demands.  If you request
information on a specific IP address,
be certain to include the exact date and time of day, along with the
timezone.

  And finally, people often use similar userids at Hotmail, Yahoo,
AOL, etc etc.