So I hate to say it but the only ones asking for this (outside of one local company for a potential conviction check) are the Indian recruiters... and they typically offer high-paying jobs from big household-name companies (like Adobe or eBay) for expertise that fits well with my resume (typically; I ignore the ones that don't). I'm a web developer if that makes any difference.
These jobs that I've proceeded with (which I didn't give that personal info for) went nowhere and I've never had even an interview with their client. I've read about the scams and spams and spoofs of shady recruiters scraping job sites and pretending to represent the employers, but on further research some of them may be legit and are required to gather this information because the client asks them to (for organization or legal reasons or to filter out people not allowed to work in the US).
However, I don't know where the line is (without maybe doing a bunch of research and calling a bunch of places), so I just say I'm not going to provide that info. Frankly big organizations should not be telling their recruiting firms to ask for that info to begin with, but what do I know?
Can someone shine more light on this or provide their experience, or any webpages I can look at to see what's going on here and how I can tell what's legit?
EDIT: This question has been marked as 'answered' through "This Recruiter wants my Social Security Number?", but this isn't just about any recruiter asking for it, as a few local trusted recruiters have asked for it for background checks (though not required it), this question is about FOREIGN recruiters, as in their company location is in another country (not The United States of America in my case) and they are calling or emailing from that country or only have names and accents from that country. So this a different question.