They're probably not doing it through smartphones, since the leaked slide deck never actually directly mentions the devices they're using to listen in on people only stating they're "smart devices": https://www.documentcloud.org/documents/25051283-cmg-pitch-d...
It is much more likely they're listening in using the microphones in smart TVs, which have much weaker privacy protections. This would also make sense since Cox Media Group is a broadcaster, thus they're much more likely to have broad access to data from smart TVs than from smartphones.
It is much more likely they're listening in using the microphones in smart TVs, which have much weaker privacy protections. This would also make sense since Cox Media Group is a broadcaster, thus they're much more likely to have broad access to data from smart TVs than from smartphones.