For non-release Firefox versions such as Nightly, Developer Edition (Aurora) and Beta, Mozilla turns on Telemetry or Usage statistics by default, not the case in general release Firefox though. This feature sends Mozilla the following information.
“Telemetry sends Mozilla usage, performance, and responsiveness statistics about user interface features, memory, and hardware configuration. Your IP address is also collected as a part of a standard web log. Usage statistics are transmitted using SSL and help us improve future versions of Firefox. ”
Telemetry experiments in Firefox
Till now we’re not aware of this: ‘Telemetry may install and run experiments from time to time’
We’ve noticed a new ‘Experiments‘ panel in add-ons manager on developer edition conveying ‘Multi-Process Firefox A/B test‘ was completed 11 days ago, I was not aware that I am part of it. If you’re interested, you can view all the current and pass telemetry experiments conducted by Mozilla here.
If you don’t want to participate in these experiments, you may need to disable Telemetry
Click on Menu, choose Options > Advanced> Data Choices tab and uncheck Share addition data (i,e, Telemetry)
If you want to help Mozilla in shaping the future versions of Firefox, don’t do that.