First it was 55 million. Then 77 million. Now, it's 2.2 billion, or pretty much every user on Facebook. That's how many people should assume that their public profile information has been scraped.
The conversation began when it came to light that Cambridge Analytica (a political research firm) had misused Facebook's search function to scrap profile data for tens of millions of Facebook's users to help the Trump campaign win the recent presidential election.