I always try to avoid sounding like an alarmist whackjob kook, but I think it's safest to start with the assumption that they both know everything. When you combine credit card transactions with location data and the various "oops, we accidentally left the microphones on, sorry, that was just supposed to be for in house testing", Flock cameras with "oops, yeah, we actually do facial recognition, not just plates," the amount these data aggregators know about us already is arguably way too much.
I was going to apologize for drifting off the AI topic, but actually, AI/ML is what's driving the processing of these massive amounts of data. They can just as easily consume all the data about you and figure out exactly what you're up to as they can find a tiny tumor in a million CT scans.
/tinfoil hat ON