I have been involved with security UI a lot in the recent years, and in the few moments that I've looked at SECURITY_UI telemetry (https://mzl.la/2NA5m1A) it was to assess that mixing all these UI events into one histogram made it terribly hard to understand what's happening. There is a need for understanding some of the things that are happening in our security UI, but we have bugs for adding new telemetry like bug 1484255, replacing the old SECURITY_UI values. My question is: Is anyone getting anything useful out of this probe nowadays? If yes, could we consider migrating the useful subset to a different probe. In the interest of lean data I propose removing the rest of this (never expiring) histogram.