--- 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"