Catalin Cimpanu, writing for BleepingComputer: Mozilla said last week it would delete all telemetry data collected because of a bug in the Firefox crash reporter. According to Mozilla engineers, Firefox has been collecting information on crashed background tabs from users' browsers since Firefox 52, released in March 2017. Firefox versions released in that time span did not respect user-set privacy settings and automatically auto-submitted crash reports to Mozilla servers. The browser maker fixed the issue with the release of Firefox 57.0.3. Crash reports are not fully-anonymized.