Given the technology of 2016 a defense company released the SpaceView 110 for non-Defense customers:
The SpaceView 110 camera magnifies its subjects with a mirror-based design more like a big telescope than a telephoto lens with lots of glass elements. It's precise enough to capture details measuring 0.31m -- about a foot across -- from the satellite's orbit 617 kilometers above the Earth's surface.
It has been reported that the limit of the resolution those satellites can provide is due to law that limits the resolution of commercial imaginary instead of being due to technological limitations.
According to Wikipedia the WorldView-4 satellite by Lockheed Martin has a mass of 2485 kg. One Falcon Heavy launch can carry 63,800 kg - more than twenty times the mass of a WorldView-4 satellite - to orbit for $90 million. However, as of 2012 the cost of the satellite itself was $835 million.
That's likely too high a price to put up hundreds of them, but they are going to be cheaper when produced at scale and Moore's law helps to drive the cost down as well. In 2017 the commercial satellite market was worth $3.061 billion.
EarthNow is a civilian project for real-time whole earth imagining that says this about their satellites' resolution:
The native video resolution, combined with image enhancement techniques, is designed to enable event monitoring and tracking applications consistent with existing and future customer requirements.
It's not clear whether that's in the realm of a 31 cm resolution but it illustrates that it's possible for a startup to track a lot.
Traditionally, the military spends a lot more on surveillance satellites and isn't keen on the public knowing about how good their surveillance capabilities are. NASA for example reuses old military tech for their earth survey satellites.
Given that aerospace is one of the areas of focus for China 2025, China is likely planning to put up a lot of spy satellites as well. China's space program is also more military lead then NASA in the US.
Given that there's huge military and intelligence value in knowing exactly what happens in another country, it's likely that both the US and Chinese military will spend significant resources upgrading their surveillance capabilities.
High resolution spy satellites aren't fixed to a geostationary orbit; a satellite that monitors North Korea at one time in the day might monitor New York at another time of the day. As a result a satellite program that's targeted to spy on countries like North Korea and Iran in high resolution will also be able to look at different countries.
It's unclear at which exact year the surveillance capabilities that match the BBC speaks about will come online, but "soon" is in itself an unclear word and it seems like it's only a matter of years until the those satellites fly over us. Societally, that makes now a good time to think about how to legislate the space. We will need to pass laws to protect our privacy in the face of EarthNow which on its homepage says it's willing to respect the privacy concerns of individual jurisdictions.
