Data Storage and Anonymization

In order to provide products and services, Yahoo! collects and stores information from user account registration and site usage. In late 2008, Yahoo! announced an anonymization policy to de-identify most user log file records after a period of 90 days*. Yahoo! is in the process of implementing this policy globally. Yahoo! takes additional steps so that data collected and used to customize advertising and some content on Yahoo! are not associated with personally identifiable information. We describe the data we store, our processes and your choices in more detail here.

* This policy will be in full effect across Yahoo! log file systems by mid-2010.

Account Information

• When you register with Yahoo! or submit information to Yahoo!, a temporary copy of that information is routinely made to prevent accidental loss of your information through a computer malfunction or human error.
• Yahoo! keeps your account information active in our user registration databases in order to provide immediate access to your personalization preferences each time you visit Yahoo!.
• If you ask Yahoo! to delete your Yahoo! account, in most cases your account will be deactivated and then deleted from our user registration database in approximately 90 days. This delay is necessary to discourage users from engaging in fraudulent activity.
• Please note that any information that we have copied may remain in back-up storage for some period of time after your deletion request. This may be the case even though no account information remains in our active user databases.

Servers Log Files

• The Yahoo! computers (called "servers") that send your web pages and advertising banners process and store an enormous amount of information every day. These computer records are called “log files”.
• Log files are used for analysis, research, auditing, and other purposes, as described above. After this information has been used, it is stored and is inaccessible. Until the information is stored, your Yahoo! ID may remain in our active server log files.

Anonymization/de-identification

• Anonymization is a process of removing or replacing personal identifiers in data records so that the resulting data is no longer personally identifiable. This is also referred to as de-identification. We use these terms interchangeably.
• Yahoo! uses a multi-step process to replace, truncate, or delete identifiers in order to de-identify data.

Log file anonymization

• Yahoo!’s anonymization policy applies to user log file data and includes searches, ad views, ad clicks, page views and page clicks.
• Yahoo! stores this data in an identifiable form for up to 90 days for most log file data.
• There are certain exceptions to this policy. Yahoo! will store a limited amount of log file data in identifiable form for up to 6 months for select log file systems involved in product and financial fraud detection and abuse management. There are also exceptions for legal obligations.

Your Interests and Yahoo!

• Yahoo collects and maintains information about your interests based on your web surfing activity when you are visiting the branded Yahoo! network of web sites as well as when you are visiting other websites in the Yahoo! advertising network.
• Yahoo! maintains information in both identifiable and de-identified forms. When you are signed-in to the Yahoo! network, Yahoo! associates your observed interests and activity with your Yahoo! account.
  • When you log in to your Yahoo! account, a cookie is placed on that computer which contains information about your interests. This is stored on the hard drive of whatever computer or device you are using when you log in. Your browsing habits on your work computer or a library computer may affect the kinds of advertisements you see when using your home computer.
  • Information that Yahoo! collects related to your activities and interests on and off the Yahoo! network is maintained by Yahoo! on its servers and is associated with Yahoo! cookies regardless of what computer or device you use to sign in to Yahoo!.
  • If you are a Yahoo! registered user who is not signed-in, Yahoo! will continue to store information about your interests based on a unique browser cookie. This cookie is an encrypted (or “one-way secret hashed”) form of a Yahoo! cookie that is de-identified from your Yahoo! account information. This de-identified cookie cannot be used by any third-parties to identify you.
  • When you are not signed in to Yahoo!, Yahoo! will use this encrypted cookie and its stored associated interest information, to match advertisements and content to your interests.

Your Preference and Opt-out Choices

• To see and/or customize the information that Yahoo! has stored about interests that we use for advertising customization, you can visit our Ad Interest Manager. Ad Interest Manager allows you to opt out of one or more specific interest categories or opt out of all interest-based ads that Yahoo! serves.
• Yahoo! refreshes cookie information for registered Yahoo! users each and every time you log in to Yahoo! on whichever computer or device you are using at that time. Accordingly, if you do not want Yahoo! to store your interests to deliver more relevant advertising, deleting your cookies will not be an effective way to express this choice. Instead, you should use the persistent opt-out that Yahoo! provides for you. If you are signed-in when you exercise the opt-out, your opt-out cookie will refreshed each time you log in to Yahoo! – even if you have had previously deleted your cookies and/or moved to a new computer.
• You can visit the Network Advertising Initiative site to see other networks that you may want to opt-out of or to use other tools to manage your opt-out choices.