SELECT COUNT(*) FROM users WHERE date_deleted IS NULL AND date_last_activity >= CURRENT_DATE - INTERVAL '120 days';

I don't think that would work, the stories said they generated fake data. There would be users presumably.

SELECT USER_ID,COUNT(*) FROM WEBSITE_CLICKSTREAM GROUP BY USER_ID

SELECT COUNT(*) FROM users would have been a start from the sound of it.

> Meanwhile, Amar purchased a list of 4.5 million real college students and their data from ASL Marketing for $105,000. Frank executives later supplemented that list — which only had email addresses for a portion of the students — by purchasing more data from an information services company.

https://www.highereddive.com/news/jpmorgan-chase-alleges-ed-...