2. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 1 Privacy Week 7 - February 28, March 2

3. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 2 Administrivia Assign roles for class debate

4. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 3 Privacy policies Policies let consumers know about site’s privacy practices Consumers can decide whether practices are acceptable, when to opt-out Presence increases consumer trust Make companies subject to FTC privacy- related enforcement Rapid adoption 1998-2001* * G.R. Milne and M.J. Culnan 2002. Using the Content of Online Privacy Notices to Inform Public Policy: A Longitudinal Analysis of the 1998-2002 US Web Surveys. The Information Society 18, 5, 245-359.

5. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 4 Privacy policy problems BUT policies are often difficult to understand hard to find take a long time to read change without notice

6. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 5 Privacy policy components Identification of site, scope, contact info Types of information collected Including information about cookies How information is used Conditions under which information might be shared Information about opt-in/opt-out Information about access Information about data retention policies Information about seal programs Security assurances Children’s privacy There is lots of information to convey -- but policy should be brief and easy-to-read too! What is opt-in? What is opt-out?

7. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 6 How are online privacy concerns different from offline privacy concerns?

8. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 7 Web privacy concerns Data is often collected silently Web allows large quantities of data to be collected inexpensively and unobtrusively Data from multiple sources may be merged Non-identifiable information can become identifiable when merged Data collected for business purposes may be used in civil and criminal proceedings Users given no meaningful choice Few sites offer alternatives

9. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 8 Browser Chatter Browsers chatter about IP address, domain name, organization, Referring page Platform: O/S, browser What information is requested  URLs and search terms Cookies To anyone who might be listening End servers System administrators Internet Service Providers Other third parties  Advertising networks Anyone who might subpoena log files later

10. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 9 Typical HTTP request with cookie GET /retail/searchresults.asp?qu=beer HTTP/1.0 Referer: http://www.us.buy.com/default.asp User-Agent: Mozilla/4.75 [en] (X11; U; NetBSD 1.5_ALPHA i386) Host: www.us.buy.com Accept: image/gif, image/jpeg, image/pjpeg, */* Accept-Language: en Cookie: buycountry=us; dcLocName=Basket; dcCatID=6773; dcLocID=6773; dcAd=buybasket; loc=; parentLocName=Basket; parentLoc=6773; ShopperManager%2F=ShopperManager%2F=66FUQU LL0QBT8MMTVSC5MMNKBJFWDVH7; Store=107; Category=0

11. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 10 Referer log problems GET methods result in values in URL These URLs are sent in the referer header to next host Example: http://www.merchant.com/cgi_bin/o rder?name=Tom+Jones&address=here +there&credit+card=234876923234& PIN=1234&->index.html Access log example

12. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 11 Cookies What are cookies? What are people concerned about cookies? What useful purposes do cookies serve?

13. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 12 Cookies 101 Cookies can be useful Used like a staple to attach multiple parts of a form together Used to identify you when you return to a web site so you don’t have to remember a password Used to help web sites understand how people use them Cookies can do unexpected things Used to profile users and track their activities, especially across web sites

14. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 13 How cookies work – the basics A cookie stores a small string of characters A web site asks your browser to “set” a cookie Whenever you return to that site your browser sends the cookie back automatically browsersite Please store cookie xyzzy First visit to site browsersite Here is cookie xyzzy Later visits

15. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 14 How cookies work – advanced Cookies are only sent back to the “site” that set them – but this may be any host in domain Sites setting cookies indicate path, domain, and expiration for cookies Cookies can store user info or a database key that is used to look up user info – either way the cookie enables info to be linked to the current browsing session Database Users … Email … Visits … Send me with any request to x.com until 2008 Send me with requests for index.html on y.x.com for this session only User=Joe Email= Joe@ x.com Visits=13 User=4576 904309

16. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 15 Cookie terminology Cookie Replay – sending a cookie back to a site Session cookie – cookie replayed only during current browsing session Persistent cookie – cookie replayed until expiration date First-party cookie – cookie associated with the site the user requested Third-party cookie – cookie associated with an image, ad, frame, or other content from a site with a different domain name that is embedded in the site the user requested Browser interprets third-party cookie based on domain name, even if both domains are owned by the same company

17. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 16 Web bugs Invisible “images” (1-by-1 pixels, transparent) embedded in web pages and cause referer info and cookies to be transferred Also called web beacons, clear gifs, tracker gifs,etc. Work just like banner ads from ad networks, but you can’t see them unless you look at the code behind a web page Also embedded in HTML formatted email messages, MS Word documents, etc. For software to detect web bugs see: http://www.bugnosis.org

18. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 17 How data can be linked Every time the same cookie is replayed to a site, the site may add information to the record associated with that cookie Number of times you visit a link, time, date What page you visit What page you visited last Information you type into a web form If multiple cookies are replayed together, they are usually logged together, effectively linking their data Narrow scoped cookie might get logged with broad scoped cookie

19. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 18 Ad networks Ad company can get your name and address from CD order and link them to your search Ad search for medical information set cookie buy CD replay cookie Search ServiceCD Store

20. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 19 What ad networks may know… Personal data: Email address Full name Mailing address (street, city, state, and Zip code) Phone number Transactional data: Details of plane trips Search phrases used at search engines Health conditions “It was not necessary for me to click on the banner ads for information to be sent to DoubleClick servers.” – Richard M. Smith

21. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 20 Online and offline merging In November 1999, DoubleClick purchased Abacus Direct, a company possessing detailed consumer profiles on more than 90% of US households. In mid-February 2000 DoubleClick announced plans to merge “anonymous” online data with personal information obtained from offline databases By the first week in March 2000 the plans were put on hold Stock dropped from $125 (12/99) to $80 (03/00)

22. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 21 Offline data goes online… The Cranor family’s 25 most frequent grocery purchases (sorted by nutritional value)!

23. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 22 Subpoenas Data on online activities is increasingly of interest in civil and criminal cases The only way to avoid subpoenas is to not have data In the US, your files on your computer in your home have much greater legal protection that your files stored on a server on the network

24. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 23 Original Idea behind P3P A framework for automated privacy discussions Web sites disclose their privacy practices in standard machine-readable formats Web browsers automatically retrieve P3P privacy policies and compare them to users’ privacy preferences Sites and browsers can then negotiate about privacy terms P3P: Introduction

25. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 24 P3P history Idea discussed at November 1995 FTC meeting Ad Hoc “Internet Privacy Working Group” convened to discuss the idea in Fall 1996 W3C began working on P3P in Summer 1997 Several working groups chartered with dozens of participants from industry, non-profits, academia, government Numerous public working drafts issued, and feedback resulted in many changes Early ideas about negotiation and agreement ultimately removed Automatic data transfer added and then removed Patent issue stalled progress, but ultimately became non-issue P3P issued as official W3C Recommendation on April 16, 2002 http://www.w3.org/TR/P3P/ P3P: Introduction

26. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 25 P3P1.0 – A first step Offers an easy way for web sites to communicate about their privacy policies in a standard machine-readable format Can be deployed using existing web servers This will enable the development of tools that: Provide snapshots of sites’ policies Compare policies with user preferences Alert and advise the user P3P: Introduction

27. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 26 The basics P3P provides a standard XML format that web sites use to encode their privacy policies Sites also provide XML “policy reference files” to indicate which policy applies to which part of the site Sites can optionally provide a “compact policy” by configuring their servers to issue a special P3P header when cookies are set No special server software required User software to read P3P policies called a “P3P user agent” P3P: Introduction

28. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 27 What’s in a P3P policy? Name and contact information for site The kind of access provided Mechanisms for resolving privacy disputes The kinds of data collected How collected data is used, and whether individuals can opt-in or opt-out of any of these uses Whether/when data may be shared and whether there is opt-in or opt-out Data retention policy P3P: Enabling your web site – overview and options

29. P3P/XML encoding <POLICY discuri="http://p3pbook.com/privacy.html" name="policy"> <DATA ref="#business.contact-info.online.email">privacy@p3pbook.com <DATA ref="#business.contact-info.online.uri">http://p3pbook.com/ Web Privacy With P3P We keep standard web server logs. P3P version Location of human-readable privacy policy P3P policy name Site’s name and contact info Access disclosure Statement Human-readable explanation How data may be used Data recipients Data retention policy Types of data collected

30. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 29 P3P1.0 Spec Defines A standard vocabulary for describing set of uses, recipients, data categories, and other privacy disclosures A standard schema for data a Web site may wish to collect (base data schema) An XML format for expressing a privacy policy in a machine readable way A means of associating privacy policies with Web pages or sites A protocol for transporting P3P policies over HTTP P3P: Introduction

31. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 30 A simple HTTP transaction Web Server GET /index.html HTTP/1.1 Host: www.att.com... Request web page HTTP/1.1 200 OK Content-Type: text/html... Send web page P3P: Introduction

32. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 31 … with P3P 1.0 added Web Server GET /w3c/p3p.xml HTTP/1.1 Host: www.att.com Request Policy Reference File Send Policy Reference File GET /index.html HTTP/1.1 Host: www.att.com... Request web page HTTP/1.1 200 OK Content-Type: text/html... Send web page Request P3P PolicySend P3P Policy P3P: Introduction

33. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 32 Transparency P3P clients can check a privacy policy each time it changes P3P clients can check privacy policies on all objects in a web page, including ads and invisible images http://adforce.imgis.com/?adlink|2|68523|1|146|ADFORCE http://www.att.com/accessatt/ P3P: Introduction

34. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 33 P3P in IE6 Privacy icon on status bar indicates that a cookie has been blocked – pop-up appears the first time the privacy icon appears Automatic processing of compact policies only; third-party cookies without compact policies blocked by default P3P: Introduction

35. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 34 Users can click on privacy icon for list of cookies; privacy summaries are available at sites that are P3P-enabled P3P: Introduction

36. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 35 Privacy summary report is generated automatically from full P3P policy P3P: Introduction

37. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 36 P3P in Netscape 7 Preview version similar to IE6, focusing, on cookies; cookies without compact policies (both first-party and third-party) are “flagged” rather than blocked by default Indicates flagged cookie P3P: Introduction

38. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 37 Users can view English translation of (part of) compact policy in Cookie Manager P3P: Introduction

39. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 38 A policy summary can be generated automatically from full P3P policy P3P: Introduction

40. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 39 Privacy Bird Free download of beta from http://privacybird.com/http://privacybird.com/ Origninally developed at AT&T Labs Released as open source “Browser helper object” for IE6 Reads P3P policies at all P3P-enabled sites automatically Bird icon at top of browser window indicates whether site matches user’s privacy preferences Clicking on bird icon gives more information

41. Chirping bird is privacy indicator

42. Red bird indicates mismatch

43. Check embedded content too

44. Privacy settings

45. Example: Sending flowers

48. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 47 Privacy Finder Prototype developed at AT&T Labs, improved and deployed by CUPS Uses Google or Yahoo! API to retrieve search results Checks each result for P3P policy Evaluates P3P policy against user’s preferences Reorders search results Composes search result page with privacy annotations next to each P3P-enabled result Users can retrieve “Privacy Report” similar to Privacy Bird policy summary

49. Demo

50. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 49 Is Privacy Finder useful? Do users care about web site privacy? Have enough web sites adopted P3P that typical search results contain sites with P3P policies? Do users have meaningful choices among privacy policies? Do users understand information provided by Privacy Finder? Does Privacy Finder influence online purchasing decisions?

51. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 50 Have enough sites adopted P3P? We weren’t sure, so we did a study…. Draft paper at http://lorrie.cranor.org/pubs/www06.pdf Previous studies examined lists of “most popular” web sites for P3P adoption, but this gives incomplete picture

52. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 51 Methodology Compiled two lists of search terms: Typical: 20,000 terms randomly sampled from one week of AOL user search queries Ecommerce: 940 terms screen scraped from Froogle front page Submitted search terms to Google, Yahoo!, and AOL search engines and collected top 20 results for each term Checked each result for P3P policy and evaluated policies against 5 “rulesets” and P3P validator Saved 1,232,955 annotated search results in database Separately checked for P3P policies on 30,000 domains most clicked on by AOL search engine users

53. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 52 Results: P3P deployment 10% of results from typical search terms have P3P 21% of results from ecommerce search terms have P3P More popular sites are more likely to have P3P 5% of sites in our cache have P3P 9% of 30K most clicked on domains have P3P 17% of clicks to 30K most clicked on domains have P3P % of domains with P3P policies Most clicked on domains

54. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 53 Results: Most popular P3P policies Typical Terms http://privacy.yahoo.com/ http://about.com/ http://privacy.msn.com/ http://disney.go.com/ http://images.rootsweb.com/ http://adserver.ign.com/ http://www.nlm.nih.gov/ http://www.bizrate.com/ http://www.superpages.com/ http://www.shopping.com/ Ecommerce Terms http://privacy.yahoo.com/ http://about.com/ http://www.bizrate.com/ http://www0.shopping.com/ http://www.shopping.com/ http://www.pricegrabber.com/ http://www.cpsc.gov/ http://www.overstock.com/ http://www.cooking.com/ http://www.altrec.com/

55. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 54 Results: Frequency of P3P-enabled hits 83% of searches had at least one P3P-enabled site in top 20 results 68% of searches had at least one P3P-enabled site in top 10 results For top 20 search results returned by AOL search engine for typical search terms: 29% return at least 1 P3P-enabled hit that matches medium privacy preferences 34% return at least 1 P3P-enabled hit in that does not share data 31% return at least 1 P3P-enabled hit that does not market without opt-in Thus, ~ 1/3 of the time AOL users will find site with “good” privacy policy in first 2 pages of results

56. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 55 Does Privacy Finder influence purchases? Studies begun and more planned…. Pay users to make online purchases with their own credit cards Some will use Privacy Finder and some will use generic search engine Experiment with more and less privacy- sensitive purchases Experiment with price-sensitivity We’re just finishing initial study of 24 college students purchasing power strips and condoms

57. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 56 Why web sites adopt P3P Demonstrate corporate leadership on privacy issues Show customers they respect their privacy Demonstrate to regulators that industry is taking voluntary steps to address consumer privacy concerns Distinguish brand as privacy friendly Prevent IE6 from blocking their cookies Anticipation that consumers will soon come to expect P3P on all web sites Individuals who run sites value personal privacy P3P: Introduction

58. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 57 P3P early adopters News and information sites – CNET, About.com, BusinessWeek Search engines – Yahoo, Lycos Ad networks – DoubleClick, Avenue A Telecom companies – AT&T Financial institutions – Fidelity Computer hardware and software vendors – IBM, Dell, Microsoft, McAfee Retail stores – Fortunoff, Ritz Camera Government agencies – FTC, Dept. of Commerce, Ontario Information and Privacy Commissioner Non-profits - CDT P3P: Introduction

59. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 58 Impacts Some companies that P3P-enable think about privacy in new ways and change their practices Systematic assessment of privacy practices Concrete disclosures – less wiggle room Disclosures about areas previously not discussed in privacy policy Hopefully we will see greater transparency, more informed consumers, and ultimately better privacy policies P3P: The future

60. Computers and Society Carnegie Mellon University Spring 2006 Cranor/Tongia/Farber http://cups.cs.cmu.edu/courses/compsoc-sp06/ 59 Evaluating information sources Don’t believe everything you read! News sources are usually a reporter's interpretation of what someone else did Conference and journal papers are first hand reports of research studies that have been peer reviewed but journals usually have more review than conferences Technical reports are usually first hand reports of research studies that have not been peer reviewed (yet) Look for subsequent conference or journal publications Web sites and books are anything goes, but books at least have an editor (usually) When possible, cite research results and technical information from peer reviewed sources Research and Communication Skills