lammert - 12:32 pm on May 16, 2010 (gmt 0)
The difference with those data and the data Google sniffed is that people have given permission in some way, or that that information must be made public based on existing laws. When you apply for a telephone number you can opt out to be listed in the phone book for example. Google didn't ask individual Wifi owners for that permission. If you read the German press statement they didn't inform the German authorities about the Wifi network sniffer in their Streetview cars. They also didn't allow the German authorities to look at equipment in a Streetview car. Only when the Germans demanded an audit they started to react.
Laws differ per country and what is prohibited in one country may be allowed in an other. This kind of privacy laws in the Netherlands forced the Dutch internet registry SIDN a few months ago for example to remove all personal information [webmasterworld.com] from the whois queries of .NL domains. What is seen as public information in one country may be private information in another.