They already do it: first of all, by controlling of import/sales of equipment, and by incentivizing citizens to tip police. Also, there are frequency control inspections which keep maps of radiotransmitting activity. It's easy to spot any new transmitter.
That only works with a small number of transmitters. If Samsung or Apple released a phone with native satellite default support, it would be impossible to police.
To be sold in a particular country every model needs certification which obviously may be a very complicated thing if that country's authorities are not happy with counter-censorship capabilities. Moreover, in many countries (including AFAIK Russia, and Chine) every shop selling satcom needs a separate certification. I am not sure Samsung, or Apple will ever risk to invest in something which cannot be legally exported to a large number of countries.
Finally, you should not underestimate how far a state can go to keep the status quo. Did we hear already:
- What, they will check every phone?
- What, they will demand our passwords?
- What, they will slow down all out-of-country traffic?
- What, they will block millions if websites, and look into every network packet?
All of these were asked sarcastically, yet every point is happening now on a massive scale.
Actually, in late 90s there were a lot of talk about 'new era', because 'internet made censorship impossible'. Hold my beer! - said state bureaucracy everywhere.
Of course, technology can sometimes leapfrog gov't capabilities, but as a rule it's a very temporary thing. Censorship is a political, and cultural problem, and it needs political, and cultural pressure to be resolved.
Btw, I don't think it only works with a small number of transmitters. In the UK they has been taxing TV watching, and managed to have a huge fleet of specially equipped vans cruising streets, identifying where are TV sets (and it's harder task then scanning for transmissions), and checking addresses against national registry. Nowadays, I suppose methods are different due to internet broadcasting, but it seems they are still capable of taking pennies for it quite successfully. FWIW, state officials love massive budget disbursements, creation, and expanding of departments, and they can use modern technologies for large-scale operations too.
