It seems like companies and organizations are always asking for your social security number. In fact, in college my University actually made us use our SSN as our school ID number. (Dumb.) You should always be reluctant to give out your SSN unless absolutely necessary, and never hesitate to ask why it's needed in the first place. A recent article in Time outlines how you can avoid using your social security number by providing alternate identification (though not without a few extra minutes spent on the phone). There was also another article a while back by the same author that detailed the risks involved with such lax use of what should be a private identifier.