Search engine optimization different signals. The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions. Patents related to search engines can provide information to better understand search engines. In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users. In 2007, Google announced a campaign against paid links that transfer PageRank. On June 15, 2009, Google disclosed that they had taken measures to mitigate the
Search engine privacy children may be an honorable goal, there are concerns about whether the government should have access to such personal data to achieve it. At other times, they may want it for national security purposes; access to big databases of search queries in order to prevent terrorist attacks is a common example of this. Whatever the reason, it is clear that the fact that search engines do create and maintain these databases of user data is what makes it possible for the government to access it. Another concern regarding government access to search engine user data is "function creep," a term