There's a big difference. If you process stuff locally, uploading the entire unprocessed data to the cloud would spark a lot of criticism. So, you are stuck run

There's a big difference. If you process stuff locally, uploading the entire unprocessed data to the cloud would spark a lot of criticism. So, you are stuck running analysis locally and uploading things like relevant ad topics. If you run your processing through the cloud, there is no optics or bandwidth cost of keeping the entire raw data as long as you want, let humans review it, and figure out which metrics to extract from it at a later point. I would say, the latter raises more privacy concerns than the former.