hello, please see the privacy policy of mozilla firefox: https://www.mozilla.org/en-US/legal/privacy/firefox.html

the preferences you're referring to are part of the Usage Statistics/Telemetry gathering and contain mere recordings of how long your browser session is open and active and no personal information whatsoever. when you have disabled the sharing of telemetry data in advanced options & then it will not be submitted to mozilla.

Thank you for your reply.

I suppose the remaining question is whether I can disable the remaining collection of the data locally since it seems unnecessary when I have reporting of that data disabled. Even reducing the "datareporting.sessions.previous.NNN" to, say, one entry per shutdown/startup (instead of the forty entries here) seems to make more sense to me.

I've always been happy with Mozilla's privacy policy btw, so this isn't a HUGE issue. Just seems an odd way to go about things imo.

This data is gathered, but is only send to the Mozilla server if you enable this under Data Choices.

• Tools > Options > Advanced > Data Choices

• about:telemetry
• about:healthreport (Firefox 21+)

I'm reasonably happy with the info provided. Marking this one as solved 'cos Mozilla still seem to be doing things right even though their browser does some silly things sometimes.

Ahem.