- From: Jonathan Rees <jar@creativecommons.org>
- Date: Sun, 14 Aug 2011 07:36:18 -0400
- To: Paul Libbrecht <paul@hoplahup.net>
- Cc: www-tag@w3.org
On Sun, Aug 14, 2011 at 5:35 AM, Paul Libbrecht <paul@hoplahup.net> wrote: > Jonathan, > > are you assuming the servers communicate to one another? They are obviously communicating - otherwise the 2nd server wouldn't show information only the 1st knows. But they do so via an hub-and-spokes intermediary, as Alan explained. There is probably no direct relationship between the two. I found the behavior disconcerting because I don't expect Expedia (or Kayak or whoever it was) to be broadcasting my travel planning behavior. I'm not saying there's a law saying they can't, and I'm not saying that the recipient has a way to know my personal identity, but I can imagine scenarios in which this leak could turn out badly for someone. > One particularly vicious communication would be from such hosts as Google Analytics which sees the URL requests made to a huge amount of servers of the earth (they don't really know the content of the web-page thanks to browser protection but URLs tell a lot). I think Facebook inserts (e.g. badges) are of the same type (because they prevent caching). > > If such a communication happens, you have all the solutions to the below experience: your browser is identified with a cookie and that is submitted to the "common" server (analytics.google or facebook). > > What would be nice is to find tests to discover these and be able to warn or to blame non-respect of the terms of use. Maybe something is doable. > > paul > > PS: Privacy libertarians are aware of these but then... many including the EU even say one should reject cookies except explicitly authorized. This is non-realistic for today's architecture. A more nuanced position is needed. Yes, that's the challenge. I wonder if rejecting cookies from transcluded content (i.e. from "visits" not directly authorized by the user) would do the trick. That is, user action would constitute authorization (to deposit a cookie), while others actions wouldn't. It may be possible to keep the overhead of 'authorization' low enough that the EU approach becomes realistic. (Related reading: Apple's deployment of the Powerbox idea http://arstechnica.com/apple/reviews/2011/07/mac-os-x-10-7.ars/9 ; also Alan Karp's work e.g. http://www.hpl.hp.com/techreports/2009/HPL-2009-341.html .) Thanks Jonathan > > Le 12 août 2011 à 17:11, Jonathan Rees a écrit : > >> Probably everyone knows this but me... >> >> I shop at expedia.com (or somewhere) for a London hotel room. Later I >> visit guardian.co.uk and see an Expedia ad for London hotel rooms. >> >> I visit guardian.co.uk in a different browser (same computer & IP >> address but Safari instead of Chrome) and instead get an ad for >> magazine subscriptions. Apparently the Guardian can tell my two >> browsers apart somehow - it's using more than just my IP address to >> decide what ads to show me. >> >> How does this work? I.e. what are browser instances doing that leaks >> their identity to servers? Is it just a lucky guess based on >> User-agent or something? >> >> (a propos our privacy & tracking discussions) >> >> Thanks >> Jonathan >> > >
Received on Sunday, 14 August 2011 11:36:57 UTC