Private data could be collected from thousands of Android and iOS apps via Yandex, the leading search engine in Russia, . The issue revolves around how this data might be available to Russia state agencies. In addition to being a search portal, Yandex also makes a software development kit (SDK) called AppMetrica, which does app usage analytics and marketing and is similar to Google’s Firebase.
Link: Yandex is causing data privacy concerns for mobile users
via blog.avast.com