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What are E-mail and the Web “like”?. Postal mail Cable TV Library Telephone Newspaper Video game They’re found in an office They’re found in a room at home. Overarching Goal. Help align user privacy expectations with reality The obvious tactics:
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What are E-mail and the Web “like”? • Postal mail • Cable TV • Library • Telephone • Newspaper • Video game • They’re found in an office • They’re found in a room at home
Overarching Goal • Help align user privacy expectations with reality • The obvious tactics: • Teach the users what it’s really like out there, or • Transform the wilderness into what it should be
Web tracking summary ual.com Request & receive main HTML page Request & receive embedded element(such as an image)while reporting referrer information dm.cs.uml.edu doubleclick.net(3rd party)
berklee.edu buy.com ual.com Cookie sharingthreat • A 3rd party content provider could track a user across all sites served by it (usually via an identifying cookie) • Some indications of interest in doing this from Internet advertising folks • Threat led to fierce opt-in/opt-out debates and lots of cookie-management software • And P3P, naturally
Web bugs • A bug is a hidden eavesdropping device • Vague definition: A Web bug is an HTML element that is • present for surveillance purposes, • and is intended to go unnoticed by users
Our definition • A Bugnosis Web bug: • is an image • is too small to see (<= 7 square pixels) • is third party to the main page (approx. RFC2965) • has a third party cookie • only appears once on page • Some other characteristics are used for secondary sorting purposes
Getting the word out • We knew there were a lot of Web bugs out there (from direct HTML inspection, and a later quantitative study) • Web bugs vs cookie sharing threat: • Web bugs harder to thoroughly explain • But have an easier take-home message: “This is evidence that someone is intentionally noting your visit” • Still very hard to identify purpose of tracking
Bugnosis: the tool • Most important user interface decision: the audience would be journalists • So we needed: • easy install/uninstall • reasonable default behavior • zero configuration • attention-grabbing runtime • a bit of gobbledygook is OK • Didn’t need: • web bug blocking behavior • browser support other than Internet Explorer
Bugnosis demo • Altace for cardiovascular risks • MSNBC Cybercrime article • use of JavaScript; latitude & longitude • Google search: “best music portsmouth NH” • referrer • Mycomputer.com's privacy policy • full probe, old junk in cookie, https • NY Times Movies pages • thrilling cookie
Bugnosis details • Proxy model(not used in Bugnosis) www.ual.com <h1>United</h1> <img src=“…” width=1 height=1> … LocalProxy <h1>United</h1> <img src=“…” width=1 height=1> …
Bugnosis details • Document Object Model /Browser Helper Object <h1>United</h1> <img src=“…”> … DocumentComplete… www.ual.com width = document.imgs[0].width…document.imgs[0].src = “bug.gif”… BHO
Bugnosis details • Advantages of BHO over proxy: • accuracy– no need to reparse HTML • image attributes– healthology • sensing in spite of SSL encryption • Disadvantages: • tightly coded to browser • interactive
Successes and Failures • Success: graphic identity gave it a legitimacy that’s otherwise unobtainable • Success: sufficiently in-your-face • Success: ability to remotely white-list sites • Failure before Success: original “drive-by” ActiveX installation • Failure: no P3P integration • Failure: insufficient tech support structure • Failure: no HTML email support
Bugnosis for Email • Web bugs in email – they know who you are! • Thoroughly breaks expectations • Trend is clearly away from 3rd party image support in HTML email readers • Yet in past 12 months we’ve seen Web bugs in emails from Pfizer, Proctor & Gamble, Roche, Orthobiotech, RJ Reynolds, GlaxoSmithKline, Experian (for Pernod Ricard)
Conclusion • Designing for journalists meant designing for the masses • Get Bugnosis from www.bugnosis.org (Windows IE only) • BTW, 3 spots in my car
Quantifying the amount of tracking • The FTC samples: from 2000 report “Privacy Online” • Of 91 “popular” sites, 84 remained in 2001 • Of 335 “random” (consumer-oriented) sites, 298 remained • Searched 100 pages on each site for Web bugs <= 4 clicks from home
Results • Popular sample: • 84 sites: 58% contained >= 1 bug • 29% of sites with bugs did not disclose them • 7,507 pages: 10% contained >=1 bug • Random sample: • 298 sites: 36% contained >=1 bug • 25,263 pages: 10% contained >=1 bug