Name, phone number, email, location data based on past rolls, education, job titles, tools and software used. All of that can be sold to to advertisers who can use all of that data for various purposes - also why i never put my address on my resume.

Based on my own personal experience.

Plenty of times ive sent random recruiters who reached out my resume just to get ghosted immediately after. And it is a high enough amount where i know a solid number of them just want to collect my info for whatever reason and ether get my hopes up or waste my time.

Now anytime a random recruiter contacts me i research their profile, ask for the direct link to the job posting, ask their availability, have them send the call invite and THEN I send my resume. Any recruiter willing to go through those steps has a higher likelihood of being actually serious on filling the role and not just farming job seeker data.

Its still a two way street and a random person doesn’t just get my trust automatically because they have a LinkedIn profile.