The website can also have an influence on many people lives since a lot of people use it as one of their main source of information etc.
[0] : https://s21.q4cdn.com/399680738/files/doc_financials/2021/q2...
And even under a different definition that would count normal browsing activity, the researchers still aren't doing scraping here. And each user is only collecting a few data points.
As far as I interpret it, only automated scraping is against the ToS:
https://www.facebook.com/apps/site_scraping_tos_terms.php
> You may not access or collect data from our Products using automated means (without our prior permission) or attempt to access data you do not have permission to access.