The US Defence Department has banned Google map-making teams from making detailed street-level video maps of American military bases after images of one ended up on the popular internet site.
A message sent to all defence department bases and installations around the country late last week told officials not to allow the mapping website to take panoramic views inside the facilities.
Google said taking such pictures was against its policy and the incident was a mistake.
The issue emerged just a few days after reports suggested that British protesters used Google Earth to help plot access to the roof of the Houses of Parliament.
Air Force General Gene Renuart, chief of the US Northern Command, said the decision to issue a formal ban was made after at least one Google crew requested and was then permitted access to a base.
He said he was concerned that allowing the 360-degree, street-level view could provide sensitive information to potential adversaries and endanger servicemen and women.
He said such views could show “where all the guards are, it shows how the barriers go up and down, it shows how to get in and out of buildings, and I think that poses a real security risk to our military installations”.
Google spokesman Larry Yu said a crew mistakenly asked for access to a base, and base officials agreed.
“It is against our policy to request access to military bases for the purpose of capturing imagery in Street View,” he said.
He said that when Google was contacted about the issue, the imagery was taken off the site within about 24 hours.
Street View is a feature on the Google Map pages that allows viewers to click on a location and see a panoramic view of that spot.
Gen Renuart stressed that the move was not an attack against the internet giant, but more a concern about secondary effects of otherwise good technology.
He said military chiefs talked to representatives at Google, and “Google was very appreciative of us letting them know that we had a concern. ... They understand the security implications, and they have given us no indication that they would not be helpful to us if we asked”.
According to the message sent by US Northern Command to military installations, Google representatives requested access to Fort Sam Houston in Texas, and were granted permission.
“Once given access they took panoramic images of the area with roof mounted recording equipment,” the message said.
“These images were placed on the internet for public access.”
The imagery included views of entry gates, barriers, the headquarters and other facilities.
The message ordered that military bases forbid such photography, report any vehicles that may have surveillance capabilities and report any incidents where access was granted.