Recruiters generally aren't interested in you at any advertised rate, or even for any particular skill. They just see Java (substitute as necessary) and contracter in the general vicinity of each other and decide to call you up and smooch you, even if the job is not a good fit and pays half what you charge. Problem is, you often have to keep in touch with recruiters to keep the flow of work, so you can't just cut them off entirely.

Burner phones and email addresses for recruiters is certainly a thing, though.