Windows XP Cookbook (Cookbooks)

Problem

You want to make sure that your privacy isn't violated when using Windows Media Player.

Solution

Using a graphical user interface

There is some controversy over whether the normal use of Windows Media Player may violate your privacy by reporting on what CDs you listen to and DVDs you view, and by the use of cookies which may allow web sites to learn that information. If you are worried, you can take these steps:

1. In Windows Media Player, choose File Work Offline. When you do that, Windows Media Player won't automatically connect to Microsoft servers, and potentially exchange information about your CD and DVD use.

2. Choose Tools Options Privacy to get to the Privacy options dialog box, shown in Figure 11-5. Uncheck the box next to Send unique Player ID to content providers. If this box is checked, your PC can be identified on web sites through the use of a special cookie put on your hard disk by Windows Media Player.

   Figure 11-5. If you want to protect your privacy when using Windows Media Player, here's where to go to change your options

3. Uncheck the box in the Customer Experience Improvement Program area if you don't want information about the CDs and DVDs you have played to be reported to Microsoft.

4. Click the Clear Caches button if you want to delete from your cache information about what CDs and DVDs you have played. Some web sites may be able to look into your cache.

5. Uncheck the box next to Save file and URL history in the Player, if you don't want the history and file information saved inside the player itself.

6. Click OK when you're done.

Discussion

There is a great deal of controversy over whether Windows Media Player violates your privacy, with some privacy advocates claiming that it represents a potential threat, and Microsoft saying that there are no privacy problems with it.

The discussion centers in large part around problems that could theoretically allow Microsoft to track what DVDs you play, and could allow for the creation of a "supercookie" on your PC that can let web sites exchange information about you.

When you use Windows Media Player to play DVD movies, each time a new DVD is played, Media Player contacts a Microsoft server and gets the DVD's title and chapter information. The server, in turn, identifies your specific version of Media Player, uses a cookie to identify the DVD that you're watching, and then records information about the DVDs you watch onto a database on your hard disk in C:\Documents and Settings\All Users\Application Data\Microsoft\Media Index.

Microsoft claims that the cookie used is an anonymous one and you can't be personally identified. The company also says that it does not keep track of what DVDs individuals watch, and that the database created on your PC is never accessed from the Internet. Instead, the company says, it's used only by your own computer the next time you put a DVD in your drive that you've played before, Media Player will get information from that database instead of getting it from a Microsoft web server. This speeds up getting the information.

The so-called supercookie that Windows Media Player creates is a unique ID number in the form of a 128-bit GUID (Globally Unique Identifier) assigned to your player and stored in the Registry. You can find it in HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\General\UniqueID. This ID number can be retrieved by any web site through the use of JavaScript. The ID number is called a supercookie because it can be retrieved by any web site. Normally, web sites can retrieve only cookies that they create and put on your PC, and so it becomes difficult for web sites to share information about you. However, this supercookie can be retrieved by any site to track you, and web sites can share this information with each other, allowing them to create a sophisticated profile about your Internet usage. Additionally, cookie blockers can't block its use.

Again, Microsoft claims that the supercookie does not invade your privacy because all it can do is identify your computer to web sites.

The Customer Experience Improvement Program can also be problematic for those who worry about privacy. When you check boxes in that area, Windows Media Player will report on your music and movie use to Microsoft.

See Also

For a full report on potential privacy problems with Windows Media Player, see articles by privacy expert Richard Smith at http://www.computerbytesman.com/privacy/supercookie.htm and http://www.computerbytesman.com/privacy/wmp8dvd.htm. Note that the article was written about Windows Media Player 8, but the issues remain the same. For Microsoft's response to Mr. Smith, see http://www.computerbytesman.com/privacy/wmp8response.htm.