[citation][nom]wintermint[/nom]I'm sure Google is hoping that the average computer user (novice) doesn't know anything about this and/or doesn't add "_nomap" to their SSID. They've really become intrusive regarding information.[/citation]
People that don't know how to do that really don't care about it. Even people that do know how to do that do not care; yes, my SSD might be associated with an approximated location on the map. So, what? Besides giving me a faster update in location-related services that I use, which is an advantage, I do not see a threat in this.
I am usually pretty sensitive when it comes to personal information, but this is not something that I would consider intrusive. People that could associate me personally to that SSID are people that know me, like my neighbors, and these people already know where I live. AFAIK, if someone passes down the street and uses a location-based service, and he is getting that location based on some data on Google's servers that know where he is because of the nearby SSIDs, that does not mean that individual knows what SSID the servers got the info from, nor can he associate me with a certain SSID. He might not even have WiFi enabled at that time, and even if he did, no matter; my network is encrypted.
This re-naming SSID business is useless: if you whip out your phone and sniff some SSIDs around, you will be able to see them even after the name change. That does not mean you will be able to log in those networks, unless they're left open. Conversely, if your phone gets the location based on the SSID datamap from the server, you will never know that for sure, it does it in the background.
The argument with the businesses is even sillier: they are public entities, and could not care less about this whole thing. Certainly, they would hope this will put them "on the map" somehow, but it doesn't.