Yandex has been the default search engine for the Russian-language edition of Firefox since early 2009, when Mozilla said it would after considering user feedback and consulting with the contributors who localized the browser for Russian speakers.

Mozilla's move caught some of its own Russian employees and contributors by surprise.

"Right now it looks like [a] one-way move driven not by users or not for users...because there is not any discussion related to this change or even [a] survey like what search engine users prefer or willing to change," said Konstantin Lepikhov in a June 5 message on the . Leipkhov's LinkedIn profile lists him as both a system administrator at Yandex and a project coordinator at Mozilla. That's not unusual, as companies sometimes dedicate all or part of employees' time to working with Mozilla on Firefox.

Alexander Slovesnik, who contributes to localizing Firefox for Russia, chimed in a well.

"There is nothing that explains this sudden change of default search engine in Firefox from most popular search provider to some other search provider," , also on Bugzilla. "This situation doesn't help to build credibility and trust in Mozilla among Russian community of Firefox users."