I was talking on the phone with my cousin today. She has worked as a substitute teacher in several schools. She is between jobs. One of the things she mentioned was that they require her to furnish her SSN on job applications. Since the wrong person could do some serious damage with your SSN, I really think it is a bad idea to have to furnish them for a job application.
I went online tonight to put a hold on a book at the library. The library is using the first 4 numbers of my SSN in their "primary identification" field.
That seems like a violation of security to me.