An HTTP cookie is data stored on a user's computer that assists in automated access to websites or web features, or other state information required in complex web sites. It may also be used for user-tracking by storing special usage history data in a cookie, and such cookies — for example, those used by Google Analytics — are called "tracking cookies". Cookies are a common concern in the field of Internet privacy. Although website developers most commonly use cookies for legitimate technical purposes, cases of abuse occur. In 2009, two researchers noted that social networking profiles could be connected to cookies, allowing the social networking profile to be connected to browsing habits.