A web scraped data dump of information available to general public was left without any access controls. Neither the act of scraping , storing or sharing that data is illegal.
Violations of t&c’s of YouTube or Insta for sure. But , would they be doing anything to pursue a case against those who scrape their sites or prevent anyone from doing so ? Platforms like these rely on having profile data made public around number of followers , location etc., it is in the platforms best interest to improve engagement with public data.
Such data would be a gold mine for marketing professionals and agencies.
Do agencies do this today, yes. Do they make that data available to public , No.