George
They obtain info from possibly illegal sources.
I received a call, text, and email about a job posting. The recruiter (name withheld to protect the guilty), stated clearly "I found your resume online". There is only ONE LITTLE PROBLEM; my resume, photo, email, phone number, etc are NOT listed online. I have even hired a private investigator to verify this. I am not a social media user. My phone is on the "do not call list". They refuse to disclose how they obtained my resume. I have a zero tolerance policy on this sort of thing.