It has been understood for awhile now that you have no expectation of privacy in public, at least as far as not being photographed, talked to, etc. Most people would probably agree that the paparazzi taking sneaky pictures of celebrities buying milk at Kroger aren't being very classy, but they'll also probably say it's fair game at that point.
Likewise, I would argue that broadcasting your SSID over the electromagnetic spectrum is public. As far as privacy is concerned (I have a slightly different opinion when it comes to security) I still haven't seen any compelling argument explaining how having your SSID mapped to a location is an any way a violation of privacy. Maybe you have one?