[liberationtech] Warn a legit site's users when tracking is possible?

[Don Marti]

There are lots of tracking protection, ad-blocking,
third-party-content-filtering, and related tools
for web browsers.  Here's a simple way for a site to
detect when a user isn't running one, and alert the
user to install something:

  http://ad.aloodo.com/

The general idea is: add an iframe on the page and try
a tracking cookie within the iframe.  If site-to-site
tracking succeeds, send a message to the containing
page.

Any decent privacy tool should block the "tracking"
here, whether it's a third-party tracking blocker such
as Privacy Badger, a third-party JavaScript filter,
or whatever.

This version just puts up a notification,
but a site might be able to use it for other things,
such as

 * finding a logged-in company intranet user with
   missing tracking protection, and filing a ticket.

 * "reverse tracking wall": hide the content of a page,
   or redirect, if tracking has succeded.

 * add a tracking protection page to a list of
   recommended tips on a content site.

The main point is to help ad-supported original
content sites by making it harder to track their
valuable audiences to less expensive sites.

Comments, suggestions, pull requests welcome.

-- 
Don Marti                    
http://zgp.org/~dmarti/
dmarti at zgp.org