That is a privacy nightmare without regulation on scrubbing extraneous information, done before upload: for example blocking out of pedestrian data; not just faces but clothing and gait, and probably also any data captured through windows.
It would be ideal to have a limited view of just the roads and signage, and have a retention plan that gradually keeps less and less historical data.
For accident review more of the data might be required, so vehicles should keep the last 24 hours of raw data.