Website operators who do not disclose third-party cookie use to consumers run the risk of harming consumer trust if cookie use is discovered. Having clear disclosure (such as in a [[privacy policy]]) tends to eliminate any negative effects of such cookie discovery.<ref name="dCj3R">Miyazaki, Anthony D. (2008), "Online Privacy and the Disclosure of Cookie Use: Effects on Consumer Trust and Anticipated Patronage," Journal of Public Policy & Marketing, 23 (Spring), 19–33</ref>{{Failed verification|date=October 2022|reason=The article says the opposite: that apriori disclosure of cookies reduces trust, and that nobody reads privacy policies anyway.}}
The [[United States]] government has set strict rules on setting cookies in 2000 after it was disclosed that the White House [[Office of National Drug Control Policy|drug policy office]] used cookies to track computer users viewing its online anti-drug advertising. In 2002, privacy activist Daniel Brandt found that the [[Central Intelligence Agency|CIA]] had been leaving persistent cookies on computers that had visited its website. When notified it was violating policy, CIA stated that these cookies were not intentionally set and stopped setting them. On December 25, 2005, Brandt discovered that the [[National Security Agency]] (NSA) had been leaving two persistent cookies on visitors' computers due to a software upgrade. After being informed, the NSA immediately disabled the cookies.<ref name="BnfI7">{{cite news |url=https://www.nytimes.com/2005/12/29/national/29cookies.html |newspaper=New York Times |title=Spy Agency Removes Illegal Tracking Files |date=2005-12-29 |access-date=2017-02-19 |archive-url=https://web.archive.org/web/20111112115242/http://www.nytimes.com/2005/12/29/national/29cookies.html |archive-date=2011-11-12 |url-status=live}}</ref>
