Who exactly are these "known contributors", and why did they have access to this data? Why did they not report the problem earlier?
And if it was downloaded "mostly" by "known contributors", who was involved with the rest of the detected downloads?
And if it was downloaded "mostly" by "known contributors", who was involved with the rest of the detected downloads?
If there was enough need to justify putting forth the effort required to export a sanitized version of these data for developers to use, then why didn't these users notice that something was wrong much sooner? And if they did notice, why weren't the appropriate parties within Mozilla notified sooner?
Could you please provide more specific details about these IP addresses that couldn't be accounted for, too? Perhaps a list of them, for instance? At least then affected users will be able to make their own call regarding their level of risk due to this incident.
Unfortunately security incidents happen, but we won't violate the commitments we have made to our users; in this case, if we revealed the IP addresses we would have another, deliberate information leak on our hands.