I don't see many open source packages collecting telemetry, so when Syncthing asked me to opt-in to telemetry I was intrigued.
I see a lot of similarities between how Syncthing and Firefox collects data. Both collect daily pings and make it easy to view the data you're submitting (in Firefox, go to about:telemetry to see your pings).
All of the data they're collecting looks relevant and innocuous. For example, there's no content about what files are being sync-ed in Syncthing. They just collect high level data like what version of the software is installed. Well done!
Syncthing even has a public data report similar to the Firefox Public Data Report. This is a great way to make it clear what data is being collected and share some data back with the users who generated it.
Interesting to see someone else doing open-source data collection in the wild!