A lawmaker in California wants to force Google Earth and similar services to blur images of so-called “soft targets” like schools, hospitals, churches and government buildings to protect them from terrorists. Assemblyman Joel Anderson, a San Diego Republican, said he decided to introduce his bill after reading reports suggesting that terrorists used online map imagery to plan attacks in Mumbai and elsewhere.

The ban, if enacted, could face legal challenges, as the right to publish images taken in public places has generally been protected by American courts. And of course, as an Associated Press article points out, images of many of the places Mr. Anderson is seeking to protect are easily available elsewhere.

That said, Google and Microsoft, and in some cases third-party imagery providers used by these companies, have voluntarily agreed to blur images of certain locations, ranging from the White House to shelters for victims of domestic violence.

Concerns that detailed satellite imagery and photographs available on Web services like Google Maps, Google Earth and Microsoft’s Virtual Earth could help terrorists plan attacks are not new. There have been reports that terrorists have used such imagery to carry out attacks in Iraq and Israel. An Indian court is considering a ban on Google Earth following reports that its imagery played a part in the Mumbai terrorist attacks.

Such talk has drawn criticism from experts who note that while virtually all technologies can be used to cause harm, their benefits typically outweigh any downsides. The security expert, Bruce Schneier recently wondered what other things legislators might consider banning to prevent terrorism: