a recruiter will get all their information including direct contact email when they respond to the fake qualified resume the recruiter submitted, then the recruiter harasses the hiring manager(s) directly on linkedin and email, or sells that information to their applicants, or other recruiters.

Or they bait and switch, saying that person is no longer available and give a second resume, knowing they have full attention of whoever is hiring. Or they would find out their phone numbers and harass them with endless calls.