Watching the Watcher: The Prevalence of Third-party Web Tracking Brent Chapman
Tera CorbariMatt Devers
Disclaimer
The views expressed in this presentation are those of the authors and do not reflect the official policy or position of the United States Military Academy, the Department of the Army, the Department of Defense or the U.S. Government.
Introduction
Benefits/LegitimacyPrivacy Concerns
Sample Webpage
1Log
Entry
1Log
Entry
1Log
Entry
1Log
Entry
4 LogEntries
adserver.com
Embedded Content
Primary means of 3rd parties reaching the end user
advertising affiliate networks
the usual suspects (doubleclick, google)
actively encouraged
Every Tag tells a story Objects (Maps,
Flash player, etc.) Images Videos Scripts Style Sheets iFrames
<EMBED>……</EMBED>
http://aruljohn.com/details.php
Technique used to increase effectiveness of advertising campaigns
Group ProfilingHow an advertiser can turn your IP
address into your digital identityYou are no longer anonymous
Behavioral Targeting
“By referring to javascript that’s hosted elsewhere, you’re basically at the mercy of that other organization…to not do evil with it”
-David Campbell, security expert
“If I wanted a backdoor into the website, this would be one of the best ways to do it.”
Urchin.js
AdBlock Plus
2o7.net armytimes.com gcion.com mavenapps.net militarytimes.co
m theplatform.com google-
analytics.com
Packet Level
• 208.79.X.X• 2o7.net• akamai.net• gbahn.net• gcion.com• militarytimes.com• webtrends.akadns.net• www-google-
analytics.l.google.com
ArmyTimes.com
Visit top 25 Alexa sitesUse AdBlock Plus to construct a
dataset of external objects
Dataset available
Analysis Methodology
Alexa Rankings(Top 25 in the United States)
1. Google2. Yahoo3. MySpace4. YouTube5. Facebook6. Windows Live7. MSN8. Ebay9. Wikipedia10. AOL11. Amazon12. Craigslist13. Blogger14. Go15. CNN16. Photobucket17. Microsoft18. ESPN19. Comcast20. Flickr21. Ask22. Weather.com23. IMDB24. WordPress25. New York Times
Most Chatty – AOL
Most Chatty – ESPN
Most Chatty – New York Times
Good Listeners – Doubleclick
Good Listeners – Google
Good Listeners – 2o7, dl-rms, Yahoo
What can we do?
Use available plug-ins and services AdBlock Plus NoScript Tor Privoxy
Explore legal protections Claim with Federal Trade Commission
This talk covered what we can see. What happens out of channel or above the user level?
How can we visualize this better?How can we organize this better?Are there more advanced techniques
out there?
Future Work
Watching the Watcher: The Prevalence of Third-party Web Tracking Brent Chapman
Tera CorbariMatt Devers