Regardless, satellite imaging technology continues to get better and better. Not long ago we measured satellite image resolution in meters; now it's down to centimeters.
Last year the US government relaxed its restrictions on commercial satellite imagery. Satellite companies can now legally distribute photos at about 25-centimeter resolution - enough to clearly make out a mailbox and four times as detailed as the previous 50-centimeter restriction.
The satellite company DigitalGlobe's WorldView-2 and WorldView-3 satellites, for example, are so powerful the government won't allow the company to release some of the images, according to Slate.
The newest US spy satellites, meanwhile, can distinguish objects less than 10 centimeters across, the BBC reports. This is less than the length of some smartphones and sharp enough to zoom in on someone's head. (Although images of either would appear blobby at that resolution.)
The US National Reconnaissance Office has a whole web of spy satellites in place. The next generation will start launching in 2018, and could include satellites with even more powerful resolutions, infrared sensors to peer through smoke, and electro-optical hardware, which can spot objects that absorb or emit electromagnetic energy.
DigitalGlobe is now selling images at about 30-centimeter resolution, according to a company brochure, but it's already pushing to have the commercial restrictions relaxed even further from 25 centimeters down to 10 centimeters. Google and government groups like the National Geospatial-Intelligence Agency, which used satellite imagery to help track down Osama bin Laden, are regular DigitalGlobe customers, according to the website.
However, Google recently bought its own satellite company called Skybox. It doesn't have satellites as sharp as DigitalGlobe's, since its resolution is a little better than 1 meter, according to the company's website. But it sounds like Google isn't worried about competing with DigitalGlobe, and it doesn't want to invade anyone's privacy (which it has been accused of at least once before on a different project).
As Skybox founder Dan Berkenstock put it during a TED Talk:
From our own computer simulations we quickly found that one-meter [resolution] really was the minimum viable product to be able to see the drivers of our global economy. For the first time being able to count the ships and cars and shipping containers and trucks that move around our world on a daily basis while conveniently still not being able to see individuals.
So while Google can't yet zoom in on your face, DigitalGlobe is lobbying for an image resolution that would make that possible for anyone willing to pay for it - as long as they aren't a threat to US national defense and security.