Firefox to US$7,500 cash reward) to researchers who discover severe security holes in Firefox. Official guidelines for handling security vulnerabilities discourage early disclosure of vulnerabilities so as not to give potential attackers an advantage in creating exploits. Because Firefox generally has fewer publicly known security vulnerabilities than Internet Explorer (see "Comparison of web browsers"), improved security is often cited as a reason to switch from Internet Explorer to Firefox. "The Washington Post" reported that exploit code for known critical security vulnerabilities in Internet Explorer was available for 284 days in 2006. In comparison, exploit code for known, critical security vulnerabilities in
RSS "link" are only required under certain conditions). Several major sites such as Facebook and Twitter previously offered RSS feeds but have reduced or removed support. Additionally, widely used readers such as Shiira, FeedDemon, and Google Reader have been discontinued having cited declining popularity in RSS. RSS support was removed in OS X Mountain Lion's versions of Mail and Safari, although the features were partially restored in Safari 8. Mozilla removed RSS support from Mozilla Firefox version 64.0, joining Google Chrome and Microsoft Edge which do not include RSS support, thus leaves Internet Explorer the last major browser to include RSS