If you stick with real companies, ie, as on the list here, v or ms org, you should be okay. the IRS has a directive they need our ssn. for some companies, they have not implemented it yet. I was also nervous when this went into play, but sticking with companies I contact via validated lists vs ones that ask me for info has done well by my confidentiality.
**********************************************************************
“Lying in bed would be an altogether perfect and supreme experience if only one had a colored pencil long enough to draw on the ceiling."
~Gilbert K. Chesterton