Like you, I have gotten pretty good at noticing "weasel words" and such in the government's statements (denials). It is clear that they take their time to make sure they word their statements ever so carefully.
Horrible battery life?
> Remember the time they kept the app open in the background on iOS devices by sending an empty audio buffer to the phone for playback?
> People started discovering that after iOS introduced the battery/power usage section in the Settings app.
They couldn't do it 24/7, of course, but they could certainly take "samples" at regular intervals or in certain locations or something. From my own experience, it doesn't seem that Facebook has ever been worried about battery life or preserving it.
Because they'd get hit by huge lawsuits and fines from governments all over the world. Europe is especially hungry to fine US companies for privacy issues.
Also it would be terrible for their reputation. Hordes of people would uninstall the app, and even delete their accounts. I would for sure.