Google StreetView's Wi-Fi Snooping

Okay, there was an intentional reason why I didn't post about this 2010 matter.

The Story via PCWorld:

Google's Wi-Fi woes started in 2010 after the company received a request from Germany's data protection authority to audit the information that Street View cars collected. As part of the project, Google was recording publicly available identifying information from Wi-Fi routers around the world in order to create a router location database to help improve the accuracy of location-based services for Android phones and other Google products. But the search giant also said its cars had mistakenly collected fragments of user data in the process.

Google's Response:

Google publicly apologized for the action, and got an external auditor to check their code, and also validate they have deleted all the personal information.

Realistic View:

So, how much personal data, could a moving car have picked up? If a person leaves his house door open, and a person standing on the street, inadvertently peeps inside and catches a glimpse of a confidential piece of paper - then who is at fault?