paper on privacy, P3P and machine-readable policy standards from Lorrie Cranor

...fwd'd from a nearby list,


"With growing recognition that website privacy policies are failing
consumers, numerous suggestions
are emerging for technical mechanisms that would provide privacy
notices in machine-readable form,
allowing web browsers, mobile devices, and other tools to act on them
automatically and distill them
into simple icons for end users. Other proposals are focused on
allowing users to signal to websites,
through their web browsers, that they do not wish to be tracked.
These proposals may at first seem like fresh ideas that allow us to
move beyond impenetrable privacy policies as the primary mechanisms of
notice and choice. Facilitating transparency and control through
easily recognizable symbols and
privacy controls that need be set only once are laudable goals.
However, in many ways, the
conversations around these new proposals are reminiscent of those that
took place 15 years ago that led
to the development of the Platform for Privacy Preferences (P3P)
standard and several privacy seal programs"

Must-read for anyone with an interest in P3P or similar mechanisms.
Some analogies there with PICS adoption too I think...



---------- Forwarded message ----------
From: Lorrie Faith Cranor <>
Date: 2 March 2011 01:32
Subject: Re: Privacy Icon Study
Cc: Mark Lizar <>,, Kevin Trilli
<>, David Singer <>

I have concerns that DNT in its current form does not provide a way
for sites to signal back that they will respect the user's no tracking
signal. Based on my P3P experience, I am also very concerned about
incentives for adoption.
There is some useful information about the DNT proposal at

I'm working on a paper reflecting on 15 years of efforts to develop
privacy icons and machine-readable privacy policies... I turned an
excerpt of it into my comments to the FTC, which you can find at
Lorrie Faith Cranor • •
Associate Professor, Computer Science and Engineering & Public Policy
CyLab Usable Privacy and Security Laboratory •
Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213

On Mar 1, 2011, at 7:47 PM, David Singer wrote:

On Mar 1, 2011, at 2:04 , Mark Lizar wrote:

Thanks Jean,
On 1 Mar 2011, at 08:38, <> wrote:

Hi all,

Your remarks are certainly very important on a theoretical point of
view, thanks for launching the discussion.

If your browser says "do not track me", you can legally sue the
company that tracked you on many juridictions. You don't need
electronic signatures or trusted third parties for that.

So you are suggesting that first, me (a web browsing user) is going to
realise that I am being tracked (even though I am on a do not track
list) then that I am going to call/email a lawyer to sue this tracking
website? Is there a possibility this would be successful?  (In any

Yes, this is not like "Do not call".  If someone violates "Do not
call", I know -- I get called.  If someone violates "Do not track" I
may not know for ages, if ever -- the tracking was internal to them
and the places they made it available to.  It is a worry, I think --
that doesn't make it useless, however.

David Singer
Multimedia and Software Standards, Apple Inc.

Received on Wednesday, 2 March 2011 10:35:04 UTC