Re: ACTION-390: alternative UA affordances for DNT choice

Let me explain the music player scenario in more detail.

I buy a small music player device from ElectroCorp.  One of its
capabilities is that it can download and play podcasts.    Most podcasts
are provided by third parties (radio stations, artists, record companies,
tech companies, etc.) and are downloaded by the music player via HTTP.
 When the music player device connects to the Internet (via my home WiFi)
and downloads podcasts, it is acting as a User Agent.

ElectroCorp offers a website, "Manage Your Music Player", that I can use to
control which podcasts I am subscribed to, among other things.   But the
music player itself doesn't offer any kind of general-purpose user

In this scenario, the user might want to limit the ability of third-party
podcast providers to track me.  To that end, the user might want to have
the music player send DNT:1 when it is downloading podcasts.   ElectroCorp
might offer an interface on their web site that lets the user turn on DNT
on his music player.   The ElectroCorp site could be absolutely clear about
what would be happening, what DNT does, and so on.   It could meet any
reasonable standard for clarity, communication, and consent.

I don't see why we would want to prohibit ElectroCorp from doing this.

On Wed, Apr 17, 2013 at 10:53 AM, Alan Chapell <> wrote:

> Please see below.
> From: "Edward W. Felten" <felten@CS.Princeton.EDU>
> Date: Wednesday, April 17, 2013 10:39 AM
> To: Alan Chapell <>
> Cc: "<>" <>
> Subject: Re: ACTION-390: alternative UA affordances for DNT choice
> On Wed, Apr 17, 2013 at 10:01 AM, Alan Chapell <
>> wrote:
>> [...]
>> That said, I'm not sure we're asking the right question here. Its not
>> "are there UA's that couldn't meet the guidelines?" -- The better question
>> is:  "are consumers better served by a standard that takes steps to ensure
>> that Users are making an informed choice?"
> This is the key question, I think.   Are we trying to enact particular
> guidelines?  Or are we trying to make sure that users are making an
> informed choice?   I think the latter is a better goal.
> The purpose of the proposed guidelines is to help ensure that the User is
> in position to make an informed choice.
> How does allowing UA's to enact DNT without offering information on what
> DNT does is help users to make informed choices?
>> If we move forward with the proposed UA guidelines, that means certain
>> UA's (e.g., dog collars, Ifttt, certain music players) won't be able to
>> enact DNT in a compliant way  at least not initially. I don't see that as
>> a bad thing given that consumers will certainly have other mechanisms where
>> they can enact a valid DNT. Can you or someone else help me understand why
>> this creates a poor outcome?
> Suppose the user doesn't want podcast providers to track their downloads.
>   If we prohibit the music player from sending DNT: 1 --- even if the user
> has gotten full notification and made an informed choice --- then we are
> frustrating the user and forcing the music player maker to offer a less
> attractive product.
> Ed, are you suggesting  that DNT is (or should be) the only way to stop
> the podcast provider from tracking downloads? I use Spotify, and that
> service offers ways to prevent others from seeing what I listen to on
> Spotify. DNT is one of many tools --- it is not supposed to be the ONLY
> tool.
> The difference here is between (a) requiring that the user's choice is
> informed and voluntary, versus (b) requiring that the user interface for
> that choice be provided directly by the UA software.    I see the rationale
> for (a).  I don't understand the rationale for (b).
> The rationale for B is this --- if you don't require those enacting DNT to
> disclose DNT functionality clearly and accurately, you frustrate the entire
> purpose of A.
>> From: "Edward W. Felten" <felten@CS.Princeton.EDU>
>> Date: Wednesday, April 17, 2013 8:51 AM
>> To: "<>" <>
>> Subject: ACTION-390: alternative UA affordances for DNT choice
>> Resent-From: <>
>> Resent-Date: Wed, 17 Apr 2013 12:52:30 +0000
>> Peter asked me to assemble some examples of User Agents offering
>> different types of affordances for DNT choice.
>> [First, for those with less experience in web standards, let's review the
>> definition of "User Agent".   The TPE spec includes a standard definition:
>> "This specification uses the term user agent to refer to any of the
>> various client programs capable of initiating HTTP requests, including, but
>> not limited to, browsers, spiders (web-based robots), command-line tools,
>> native applications, and mobile apps [HTTP11<>]."
>>    HTTP requests are used for many purposes beyond loading HTML pages for
>> display in browsers.  Although we might be tempted to think of "User Agent"
>> as synonymous with "browser," there are many UAs that are not browsers.]
>> User Agent functionality is built into many types of consumer electronics
>> or "smart object" products, including alarm clocks, pedometers, audio
>> players, car electronics, bathroom scales, and even dog collars.   (The
>> collar reports your dog's location over time.)   These are not
>> hypotheticals; they are all real products on the market.   Many products of
>> this type do no offer a rich user interface on the device itself.  Instead,
>> they offer control and interaction via a web site provided separately from
>> the product itself, which the consumer accesses using their ordinary
>> desktop browser.
>> For example, a music player device might offer the ability to subscribe
>> to podcasts, with the device automatically downloading new podcast episodes
>> from subscribed-to podcasts as they become available.   When downloading a
>> new podcast episode, the player device would be acting as a user agent
>> (initiating an HTTP request).  Yet the player device might not offer a user
>> interface with rich controls.  Instead, the user might set up and control
>> their podcast subscriptions via an external website affiliated with the
>> device.
>> In this case, it is possible to offer the user DNT choice via the
>> external website.  But note that this choice would not be offered through
>> the user agent (the music player device) itself---and the external website
>> is not a user agent at all.  Therefore a spec that required choice to be
>> offered *directly by* the user agent would not be implementable in this
>> scenario, while one that merely required clear choice *with respect to* the
>> user agent would be implementable for this type of user agent.
>> Another type of UA that can't offer a direct DNT affordance to the user
>> is a service that acts asynchronously on the user's behalf.   One example
>> is Ifttt.   You tell Ifttt a "recipe" such as "rebroadcast all of my
>> Twitter tweets as Facebook wall posts" or "clip any Facebook photo tagged
>> with my name and upload it into Evernote", etc.   Then Ifttt periodically
>> accesses the various sites on your behalf to carry out the recipes.  When
>> Ifttt accesses these sites, it is acting as a User Agent, but you are not
>> present and this UA doesn't offer you a direct user interface.   You can
>> control the status of your Ifttt account via an external control panel,
>> which is not a User Agent.   Again, notification and choice are possible
>> *for* the Ifttt User Agent, but not *through* the User Agent itself.
>> This should give an idea of some of the scenarios that can come up.
>> There are others that pose different challenges, such as command-line
>> tools, or tools that user HTTP "in the background" to update code or data
>> in an app, or code that isn't allowed to offer a rich user interface for
>> security reasons.   (A rich UI can be used, e.g., to trick the user into
>> entering a sensitive password, so some systems block less-trusted code from
>> displaying a rich or large UI.)
> --
> Edward W. Felten
> Professor of Computer Science and Public Affairs
> Director, Center for Information Technology Policy
> Princeton University
> 609-258-5906 

Edward W. Felten
Professor of Computer Science and Public Affairs
Director, Center for Information Technology Policy
Princeton University

Received on Wednesday, 17 April 2013 15:14:53 UTC