The fact that I could read the PHP in question to see what it's doing is beside the point. Setting aside Adam's recent (in the last hour) ninja-edit of the FAQ to cover this topic, adding a phone-home function to Observium that isn't/wasn't advertised and (assuming you've discovered that Observium phones home in the first place) can't easily be opted out of is disingenuous and worrying.
Adam's dismissal of my legitimate question as trolling is pretty fucking disingenuous as well, given the nature of what we're talking about. Equally, the suggestion that I'm only asking about this since Adam published the usage stats page 'earlier' is pretty facile. If that page had existed when I discovered this behaviour, I wouldn't asking the question.
Finally, this phone-home feature is relatively new as far as I can tell and I don't recall an email to the list announcing it.
Ah well, Observium - it was nice while it lasted.
Dermot