You don't need a television set to get a good look at the destruction of the Gulf Coast caused by Hurricanes Katrina and Rita.
These days, anyone can fly over the Gulf Coast — and the Grand Canyon, downtown Paris or a U.S. military base in Iraq — with a personal computer and a click of the mouse.
Google Earth (search), a satellite imagery-based mapping product that combines three-dimensional buildings and terrain with mapping capabilities and Google search options, allows users to zoom in on any location around the globe. Just type in a street or exact address, and take a slightly dizzying flight to your end destination.
"Google Earth utilizes broadband streaming technology and 3D graphics, much like a videogame, enabling users to interactively explore the world — either their own neighborhood or the far corners of the globe," John Hanke, general manager for the Google Keyhole group, which developed the application, said when the product launched at the end of June.
But some are questioning whether Google Earth also provides terrorists with readily accessible data that they can use to attack the United States or other countries, particularly when users can zoom in from space level to street level.
"You would not want terrorists getting ahold of some of this information, because it makes their jobs a lot easier," said Steve Emerson, a terrorism analyst and executive director of The Investigative Project.
"If a terrorist doesn't have to leave the confines of his sanctuary and can remotely view the entire infrastructure, vulnerability points, access points of a sensitive place that he wants to bomb — wow, his job has already been made 90 percent easier."
Google Earth currently focuses higher resolution on larger U.S. metropolitan areas. But the satellite images can be up to three years old, and high-resolution imagery is not as available in areas like the Sudan, for example, as it is for New York City.
So if terrorists were relying on Google Earth for information on a target, some experts said, they may want to think again.
"If I was going to be going through all the trouble to conduct a well-planned assault on a nuclear power plant, I'm not going to trust some Web site to do my intelligence collection," said John Pike, founder of GlobalSecurity.org. "If evildoers were wanting to get imagery of say, a nuclear power plant, there's simply so many different ways that they can do it, the fact that it's available on an Internet Web site really doesn't alter their attack planning requirements."
A Virtual Trip Around the World
Adding different "layers" to the area you're "visiting" gives you exact locations of nearby parks, schools, terrain, railroads, geographic features, restaurants, ATMs, banks, subways, roads, and borders. Google Earth also allows users to plot driving directions and have the program drive through the route. Users can also add their own tabs to the maps.
The National Oceanic and Atmospheric Administration provided Google Earth with images of New Orleans, Mississippi and Alabama, which were hit by Hurricane Katrina last month.
Google Earth members created overlays that drape on top of existing satellite images, which help views compare before- and after-Katrina images. The online community Google Earth Community BBS provides helpful hints on how to use overlays, among other Google Earth tools.
"I think in terms of the software program itself, it's very user friendly … it's very self-intuitive in that you can either enter an exact address or just a town or even a business or landmark in that town and it will take you at least to what it thinks it is," said Shane Blair, a senior business analyst for Citigroup's technology infrastructure.
"In some ways it enables the user to take a sort of virtual trip because you can be sitting in New York and say 'the Eiffel Tower' and the thing is going to show you as it zooms you out of the city, over the ocean to Paris."
A new huge fan of Google Earth, Blair recently searched his hometown of Midlothian, Texas, for familiar spots.
"I couldn't remember some of my friends' addresses or anything like that. I would just enter a street name or put the town name and then I could just zoom down and actually see the streets on the screen and follow the road as if I was driving on the road," he said. "I could zoom down close enough to see a car parked in the driveway if it's there."
The real estate, travel and tourism industries use Google Earth extensively. Prudential Preferred Properties, for instance, launched a plugin for Google Earth last month that allows users to search its listings by city, property type and price. The listings are automatically updated four times a day.
"We believe this cutting-edge technology will be a wonderful asset to both our agents and our clients," Prudential Preferred Properties President Jim Roth said in a statement. "We can sell real estate more quickly and efficiently since clients can gain almost all of the information they would want before making a trip to visit the property themselves."
There has been some concern that the views seen on Google Earth and other products, such as Google Maps or Microsoft's "Virtual Earth," show too much for comfort.
Some Australian officials decried the fact that images of the Lucas Heights nuclear reactor in southern Sydney could be seen in such detail on Google Earth. Google says they have not received any formal requests from governments to censor any images.
It's basically up to the individual government to determine what images they don't want provided to companies for distribution.
No Data Restrictions
The U.S. Geological Survey is in charge of releasing global images taken with U.S. government satellites. Ron Beck of the land-remote sensing program at USGS told FOXNews.com that it's his agency's job to take moderate-resolution images and dispense them to anyone who wants them.
Third parties can either buy satellite images or can just get the "quick look" images that give visual representations but not the full data that scientists use that show, for example, detailed vegetation and river quality more dramatically.
Beck said it's his understanding that Google Earth has mostly been using the "quick look" images satellites. Google Earth and Microsoft's Virtual Earth also obtain their data from USGS' Web-based national maps, which include some aerial photography that has been collected over many decades.
"Most of those data can be downloaded at no costs … we don't put any restrictions on the distribution of the data," Beck said.
He stressed that USGS images don't show anything smaller than 15 meters, or the size of a tennis court.
"The commercial satellites that are up there — and there are a whole series of commercial satellites up there, give you higher detail and Google Earth, as I understand it, has made some arrangements to use some of those images as well," Beck said.
Those commercial firms sell their data to government agencies, mainly defense institutions. Some companies can show detail as small as 1 meter across but they must receive clearance from the military to release them.
Even though Google Earth allows users to zoom in on defense installations in Iraq (search), for example, company officials say they have not yet heard any formal complaints from the Pentagon.
"Google Earth contains both satellite and aerial imagery. We take any concerns about Google Earth and Google Maps seriously, and in fact have proactively reached out to the Defense Department to see if they have any concerns," said Google spokeswoman Eileen Rodriguez. "They have not so far informed us of any, but we're always willing to listen if they do."
There so far doesn't seem to be that much concern, for one, about such images giving away troop locations of Americans in Iraq.
"The bottom line is that the U.S. government looked at this imagery and decided that it was OK for it to be publicly released," added Pike of GlobalSecurity.org. "The licenses that these satellite companies operate under allow the U.S. government to decide what imagery would jeopardize national security and hold it from release.
"The fact that the government authorized the release of this imagery I think indicates that the Defense Department decided that the release of this imagery was not going to jeopardize the troops."
And as long as private companies get the green light to sell the images, Google and others can buy them freely.
"These imagery products available on the Web or commercially are a tool without question that can be used by terrorists or insurgents," said Ret. Marine Lt. Col. Bill Cowan, a FOX News military analyst. "But in the final analysis, there's just no way to stop their production, their availability out there for the general public — whether they be bad guys or good guys."
He added: "As we look down the future, we should expect that more imagery is going to be out there. Some of it's going to be at better resolution and we should always operate on the premise that the bad guys — terrorists or insurgents — have access to that kind of information."
But some government officials and outside experts note that the United States doesn't want to get into the business of "shutter control" (search), which is basically the practice of censoring satellite imagery.
"Possibly, in a post-Sept. 11 environment, we do need to think about restricting the availability of information that would be useful to terrorists," Pike said. "But if we're going to do it for online satellite imagery, there are a lot of other sources of similar information that we're going to have to try to restrict as well."
FOX News' Dan Gallo contributed to this report.