Re: Action 32 -- Proposed language for site-specific exception

One advantage of a tech-specific requirement (placing an opt-in cookie) would be the relative simplicity for users to clear all of their tracking opt-ins — just clear your cookies. If some sites use fingerprinting and other sites use localStorage and yet others use cookies to store a user's opt-back-in status, then a user would have to manually manage on a site-by-site basis if they decided they wanted to opt-out again.

We might be able to address this concern with some variation of the Tracking response header / well-known location such that user agents could detect when a user is being tracked because of an opt-back-in and give the user a pointer on how to clear it. This is also an advantage of the user-agent-managed list of site-specific exceptions: the user agent could make it easy for users to see and modify the list of site-specific exceptions.

Thanks,
Nick

On Nov 9, 2011, at 8:14 AM, Shane Wiley wrote:

> Thank you John – helpful starting point.  I’d suggest we not assert only a cookie as the “exception” memory mechanism but a recommended one.  It could be equally viable and appropriate to store this information in a registration key, a browser setting, or some other technical mechanism.
>  
> - Shane
>  
> From: John Simpson [mailto:john@consumerwatchdog.org] 
> Sent: Wednesday, November 09, 2011 8:00 AM
> To: Aleecia M. McDonald; Nicholas Doty
> Cc: public-tracking@w3.org Group WG
> Subject: Action 32 -- Proposed language for site-specific exception
>  
> Proposed language for a site-specific exception using a cookie:
>  
> When a DNT enabled user agent grants a site-specific exception, the site places a site-specific opt-in cookie on the user agent allowing the site to respond as a First Party.  The DNT header must remain enabled so that if the user returns to the site, both the user's general preference for DNT and the site-specific exception will be clear.  This could enable the site to provide a higher level of privacy than if DNT were not enabled, but less than if the exception had not been granted. Opt-in site-specific exception cookies should expire within three months, enabling the site to determine periodically whether the user intends to continue to grant an exception.
>  
> ----------------
> John M. Simpson
> Consumer Advocate
> Consumer Watchdog
> Tel: 310-392-7041
>