[tor-talk] google analytics says it can track across separate domains

[Joe Btfsplk]

On 5/19/2012 5:00 PM, Mike Perry wrote:
> If you prevent the associated identifier transmission and 
> fingerprinting issues, "web beacons" do not link your activity on one 
> url to another. If we prevent identifier transmission and 
> fingerpritning, web beacons will see both visits, but they do not know 
> it is the same user on both visits. The reason we don't care that they 
> can still see both visits is because the urls you visit can and do 
> simply sell their logs to third parties already. If a site tries to 
> deploy web beacons, you should assume they are also selling your data 
> to whoever is buying, regardless of what the browser actually does.
>> Presumably, as they are loaded w/ pages, even w/ disk cache turned
>> off, they can still be stored in memory cache&  still track users,
>> unless memory cache is disabled.  True?
> Not exactly. In Tor Browser, cache is isolated by url bar domain,
> meaning that the cached copy of a web beacon that was loaded under one
> url bar is actually *not* used when the same web beacon is loaded under
> a different url bar.
>
> Though in interest of full disclosure, you'll notice that one of the
> "tbb-linkability" tagged bugs is an issue with this cache isolation
> specifically for images:
> https://trac.torproject.org/projects/tor/ticket/5742
>
> Tracking scripts are correctly isolated in the cache, however (which is
> more important, as many tracking scripts *do* embed unique identifiers
> to get cached and used when the user clears cookies).
I used the term "web beacon" too loosely, rather than as specifically 
1x1 GIFs.  Similar to how "trackers" is often used to describe a single 
beast, regardless of their function.
There are of course, several types of technology that are often loosely 
referred to under the general "tracker" term.  I didn't do a good job, 
but in my original question a month or so ago & again today, I meant to 
include java script trackers as well.  Many of the "true" trackers - w/ 
cross domain tracking ability - are java script.  Google Analytics is 
only one of many.

I think that those voicing a concern w/ these & TBB, were concerned w/ 
the trackers most difficult to stop.  Are you saying that * tracking 
scripts * are ALSO isolated per URL domain in the cache (see quote 
below)?  So that cross domain tracking isn't possible in TBB?  If that's 
not correct, then there's still a big problem for now.

> Tracking scripts are * correctly * isolated in the cache, however (which is
> more important, as many tracking scripts*do*  embed unique identifiers
> to get cached and used when the user clears cookies).

When you speak of sandboxing:
> Flash has tons of fingerprinting and proxybypass issues hidden in its binary blob. We
> really need a full sandboxing technology to make it safe to uniformly enable.
If running an app in something like Sandboxie, (maybe you mean a diff 
scenario), it is protecting the OS / machine from the APP.  It doesn't 
stop a browser (or, I assume, trackers; Flash) from connecting to the 
internet.  Maybe it would have value once the browser is closed, Flash 
proxy bypass has already occurred.  Unless you're talking about 
something else.