I know HR has MY SS on file....period. Anything out of the office, I hate to say it, but from now on.......I May just forget My # as I am filling out a form/s. The 3 might get replaced with a 4 and so on. And if it comes back to bite me in the ass, then at least I know for sure that They are really looking at it for information. Lots of great points on this thread.
(All the above are MY opinions/suggestions ONLY....AND, I like to bust ball's, it's called having a sense of humor. In other words, no intent to offend anyone, so get over it)