The privacy watchdog has rejected a complaint against Google Street View.
Campaign group Privacy International argued that Street View breached the privacy of people accidentally caught on camera by Google's photo cars.
But David Evans, the ICO's senior data protection practice manager, compared being captured by the service to passers-by filmed on television news camera or football crowds in the background on televised matches.
It would not be in the public interest to "turn the digital clock back", he said.
"In the same way, there is no law against anyone taking pictures of people in the street as long as the person using the camera is not harassing people," he said.
"Google Street View does not contravene the data protection Act and, in many cases, it is not in the public interest to turn the digital clock back.
"In a world where many people Tweet, Facebook and blog, it is important to take a commonsense approach towards Street View and the relatively limited privacy intrusion it may cause."
He said Google should routinely blur images of people's faces and car number plates.
The company was responding "quickly" to requests from people to have particular images deleted, he said.
When the service launched, users discovered a man walking out of a sex shop and another being sick outside a pub.
