The latest study, conducted by SmartWare for Mozilla and released November 14, 2006, concluded that the anti-phishing filter in Firefox was more effective than Internet Explorer by over 10%. The results of this study have been questioned by critics, noting that the testing data was sourced exclusively from PhishTank, which itself is an anti-phishing provider. The study only compared Internet Explorer and Firefox, leaving out (among others) Netcraft Toolbar and the Opera browser, both of which use data from PhishTank in their anti-phishing solutions. This has led to speculations that, with the limited testing data, both Opera and Netcraft Toolbar would have gotten a perfect score had they been part of the study.