As things currently stand, the overwhelming majority of threats to and abuses of privacy are performed automatically over large userbases, typically by, or with the cooperation of site administrators, but occasionally by programs written to "scrape" the data from large sites.
This is not a large site, I administer it myself (on real physical hardware that I actually own), and the personal information posted on this site does not adhere to any standards that would make it more easily aggregated and analyzed (e.g. vCard).
On top of all that, the information provided is far more useful for sending me gifts, cheques, etc. (which has happened) than for trying to find grounds to deny me insurance benefits, incriminate me, etc.
Finally, (just like user information on a site with little to no regard for user privacy) there is no reason to believe that the information provided is actually correct.