After applying for a job posting I was contacted by a hiring agency that I haven't heard of before and after asking me questions about my work history he asked for the last four digits of my social. I became very uncomfortable at that point and told him I wouldn't be giving him that information over the phone. We ended the conversation after he said the employer was requesting that information before going anywhere further. Thinking about the recruiter having a very American name both first and last but having a very heavy accent I'm glad I didn't proceed.