Sure; I'm just complaining about the _existence_ of `browser.newtabpage.activity-stream.feeds.telemetry`. I'm not comfortable having tracking so near user data.
Now that I'm not on a mobile and can actually look at the code, it looks like it's defined at [1]. I must be reading TelemetryFeed.jsm wrong, though, because that says addSession() holds on to the URL (as .page) and createPing() puts it into the ping...
Tracing back through the code, this is only triggered with a URL by the RemotePages watcher, which notifies when the URL matches one of a whitelist. The only whitelisted URLs currently are about:home, about:newtab, and about:tabcrashed.