Street View allows users of Google's maps to view 360 degree photographs of streetscapes in towns and cities that have been catalogued by Google cameras. The company's distinctive cars with cameras attached were spotted on the streets of London for the first time last week.
Pressure group Privacy International wrote to Google's senior privacy counsel Jane Horvath last week to explain its reservations. "You may be aware that Privacy International has stated, both privately to Google legal staff and to the media, that we are concerned about a number of potential violations of national law that this technology may create," wrote Simon Davies of Privacy International.
Davies said that if Google did not satisfy him that it had taken great enough account of users' privacy he would complain about the service to the Information Commissioner's Office (ICO). "In our view they need a person's consent if they make use of a person's face for commercial ends," Davis told the BBC after sending the letter.
Google, though, has implemented blurring technology in order to protect the identities of people and vehicles pictured. The technology blurs faces and vehicle number plates allowing high quality images to contain indistinct people and number plates.
Horvath has written back to Davies explaining that the face and number plate blurring technology has been in place since May. Though she conceded that it is not perfect, she said that it does protect privacy.
"As with all such systems operating at this scale our blurring technology is not perfect – we occasionally miss a face or license plate, for example if they are partially covered, or at a difficult angle," said Horvarth. "However, we tested the technology thoroughly before launch and I am confident that it finds and blurs the vast majority of identifiable faces and license plates. For the few that we miss, the tools within the product make it easy for users to report a face or license plate for extra blurring. As always, users can still ask for their image to be removed from the product entirely."
Street View had its first European launch last week, covering the route of the Tour de France cycle race. The technology is visible there and while figures are very clearly viewable, faces and number plates are blurred.
Street View has already proved controversial. One lawsuit in the US has been filed by a couple who argued that the pictures of their property were intrusive.
Google has long said, though, that it would adapt its service for the stricter privacy regimes of places such as Europe and Canada.
"We've always said that Street View will respect local laws wherever it is available and we recognize that other countries strike a different balance between the concept of 'public spaces' and individuals' right to privacy in those public spaces," said Google global privacy counsel Peter Fleischer in a blog post last year. "There's an important public policy debate in every country around what privacy means in public spaces. That balance will vary from country to country, and Street View will respect it."
The Google cars, which have a logo on their door and a metre-high camera rig on their roof, have been sighted in Edinburgh, Cardiff, Birmingham, Leeds and Middlesbrough in the past week.
"Our users have been asking for the service ever since we launched in the US and we are very excited about bringing it to Europe," a Google spokeswoman told OUT-LAW.COM last week. "Soon people from all over the world will be able to explore the beautiful cities of Europe right from their desks."
Struan Robertson, editor of OUT-LAW.COM and a technology lawyer with Pinsent Masons, said that the legal issues are academic.
"The Data Protection Act is irrelevant to Google unless people can be identified in the scenes. There will be some cases where the blurring technology misses a face, but that's not a reason to shut down the service. These people can complain to Google if they're upset by the image and they can have the photos removed. If they've suffered damage and distress as a consequence of the photographs, they could sue."
"The other relevant legal issue is our human right to a private life. But that's unlikely to be breached by photos of people in a street when the individuals are not the focus of the shots," he said.
Robertson pointed to a recent Court of Appeal ruling on that right in a case involving children's author JK Rowling.
The judge said that in any future case in which a person happened to be in a photograph taken on the street they would be unlikely to have a reasonable expectation of privacy. The judge was making the point that Rowling's child in that case was the subject of the photograph and not just a bystander.
"I suspect most people will welcome Google Street View, rather than find it alarming," said Robertson. "The face and number plate blurring strike me as sensible steps to minimise the privacy risks."