What Questions Should We Ask?

With the rise of IOT we can have sensors - cameras, microphones, thermometers, etc. - everywhere; all pumping "big data" that we can then analyze with computers and AI - looking for patterns, looking for anomalies.
One way to frame it is - coming from Peter Diamandis - is that we will live i a world where it is possible to know anything and everything. Let's set aside the privacy implications... and focus on if we can get the answer to any question what questions should we ask?