
Judging by what the estate's lawyers are saying, you would think yes, as they are denouncing the public view of MJ's social security number for "privacy" reasons.
But according the the FAQ of the Social Security Administration's website, http://www.ssa.gov/history/hfaq.html , an individual's social security number becomes searchable after they die:
(click to enlarge)

However, in the estate's lawyer's letter to Joe Jackson's attorney Brian Oxman, posted on TMZ (http://tmz.vo.llnwd.net/o28/newsdesk/tmz_documents/1231_jackson_ucla_wm.pdf)
they firmly believe that the public should NOT have access to the SS#:
(click to enlarge)
