Wouldn't demanding money be blackmailing?
A story from one of my startups: A student reached out to us regarding a security vulnerability on the website, demanding money for it. He refused to say what it was or provide evidence at first, so we couldn't assess it. He said he'd disclose it to others if we didn't.
I definitely felt blackmailed. I am not a lawyer but it felt illegal. Maybe someone can chime in to say if it is?