Yandex' open source ClickHouse analytics database also had significant engineering effort applied to enable selective and permanent deletion of data in what use

Yandex' open source ClickHouse analytics database also had significant engineering effort applied to enable selective and permanent deletion of data in what used to be an append-only database that could only drop whole partitions. Regulation works, and the large tech companies are the most likely to be compliant, since they have the most to lose and have mature compliance and legal processes. Google is particularly good about this - consumer trust is their #1 asset.