But there is definitely a need for recruiters in the wider industry (especially to help big firms that are not in the technology industry but need programmers, eg finance, insurance, healthcare etc. Good programmers are hardly banging on their door and usually the firms have to chase the talent.)
My point is, sure, send pesky recruiters who bother about positions that clearly state "no recruiters" to that form. But don't try to waste their time just because they contacted you out of the blue. There's nothing wrong or illegal about a company to cold-calling/emailing another about potential services and so just politely say "no thank you, we don't pay recruiter fees" and move on.