Yahoo Limits Retention of Personal Data to 90 days
nytimes.com
nytimes.com
"Under the new policy, Yahoo will delete the last eight bits of the Internet Protocol, or I.P., address associated with a search query after 90 days."
This is the same trick that Google is trying to play on us. Basically, they still retain all information they use to track you indefinitely, except for 8 bits of it. With decent data-mining software you can still identify somebody pretty accurately even without those 8 bits.
Here is a better story that gives better information: http://tech.yahoo.com/news/nm/20081217/wr_nm/us_yahoo_data
"Yahoo will also hide cookie data related to each search log and strip out any personally identifiable information, like a name, phone number, address or Social Security number, from the query itself."
There's much more personal information in a few month of search logs than that.
After all, it's just 33 bits you need to identify a person.
That's misleading. An IP address can't always uniquely identify the client computer. For starters, people can use proxies or anonymizers.
"Yahoo will also ... strip out any personally identifiable information, like a name, phone number, address or Social Security number"
Who is giving their SSN to Yahoo, and why??