https://measurement.cs.princeton.edu/privacystudy/
Please see https://www.spamhaus.org/consumer/definition/
«Spam is an issue about consent, not content. Whether the Unsolicited Bulk Email («UBE») message is an advert, a scam, porn, a begging letter or an offer of a free lunch, the content is irrelevant — if the message was sent unsolicited and in bulk then the message is spam,» or in this case a student at Princeton University.
The behavior observed here is someone scraping webpages looking for email addresses and then sending emails to those email addresses without permission.
princetonprivacystudy.org 35.169.11.79