From: Robert Hettinga <rah@shipwright.com>
Date: Tue, 28 Jan 1997 17:26:25 -0800 (PST)
To: cypherpunks@toad.com
Subject: AltaVista sprouts a hole ...
Message-ID: <199701290126.RAA11363@toad.com>
MIME-Version: 1.0
Content-Type: text/plain



--- begin forwarded text


Sender: e$@thumper.vmeng.com
Reply-To: Russell Stuart <R.Stuart@rsm.com.au>
MIME-Version: 1.0
Precedence: Bulk
Date: Wed, 29 Jan 1997 08:07:27 +1000
From: Russell Stuart <R.Stuart@rsm.com.au>
To: Multiple recipients of <e$@thumper.vmeng.com>
Subject: AltaVista sprouts a hole ...

From: risko@csl.sri.com (RISKS List Owner)
Newsgroups: comp.risks
Subject: RISKS DIGEST 18.77
Message-ID: <CMM.0.90.1.853810937.risko@chiron.csl.sri.com>

RISKS-LIST: Risks-Forum Digest  Monday 20 January 1997  Volume 18 :
Issue 77

   FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS
(comp.risks)
   ACM Committee on Computers and Public Policy, Peter G. Neumann,
moderator

***** See last item for further information, disclaimers, caveats, etc.
*****
<snip>
------------------------------

Date: Fri, 3 Jan 97 23:52:00 +0100
From: Anders Andersson  <andersa@Mizar.DoCS.UU.SE>
Subject: Leaking WWW surfer interest profiles

I notice that AltaVista's inline advertisements link to a server outside
Digital, "ad.doubleclick.net", and that the URL includes the user's list
of
keywords being searched.  I'm concerned that these URL's may
occasionally
leak information about the user's interests and inclinations to third
parties, information which the user may prefer to keep private.

This is not a new problem that appeared with the inline ads, since also
the
Referer: field of the HTTP protocol discloses to a target server exactly
what AltaVista index page led the user to it.  However, this requires
that
the user willfully follows that link.

If sensitive information being leaked via the Referer: field is a
problem,
the user may obtain client software that withholds Referer: data, either
conditionally or unconditionally.  Also, a user who has asked AltaVista
for
"gay" pages is probably not too concerned about accidentally disclosing
this
fact to the maintainer of said "gay" pages.

However, the doubleclick.net ads appear to bear no relationship to the
keywords being searched, and they appear not only in the URL for the
hyperlink to follow, but also in the IMG SRC URL.  This means that in
order
to avoid disclosing my keyword lists to doubleclick.net, I have to
disable
automatic loading of inline images when using AltaVista!

Why is it that when I perform a search for, say, "gay OR nazi AND
scientology", AltaVista tricks my browser to give this very search
string
away to an advertising company by means of an inline image (the contents
of
which has nothing to do with my search)?  I think I can trust the
AltaVista
maintainers not to save my keyword lists for future analysis, but what
about
an advertising company?

It's kind of serendipity reversed.  When you open a book to look up
information on a specific subject, the book scans your mind to find out
what
other interests and hobbies you have.

Anders Andersson, Dept. of Computer Systems, Uppsala University
Box 325, S-751 05 UPPSALA, Sweden   +46 18 183170   andersa@DoCS.UU.SE

------------------------------

<snip>


Regards
Russell Stuart
Software Development Manager
RSM Technology PTY LTD
----------------------
Phone: +61 7 3844 9631
Fax:   +61 7 3844 9522
Email: R.Stuart@rsm.com.au



--- end forwarded text



-----------------
Robert Hettinga (rah@shipwright.com), Philodox
e$, 44 Farquhar Street, Boston, MA 02131 USA
"The cost of anything is the foregone alternative" -- Walter Johnson
The e$ Home Page: http://www.shipwright.com/rah/
FC97: Anguilla, anyone? http://www.ai/fc97/
"If *you* don't go to FC97, *I* don't go to FC97"