They aren't giving up, they are just waiting as they "only have to get lucky once"
Meanwhile those who recognize the issue instead must live by the maximum "Eternal vigilance is the price of liberty"
We should be in a world where "I want to ban encryption" results in "Of course not, and your career in politics is now over". We should be in a world where "I want to ban encryption" results in "No, in fact here are a bunch of laws enshrining the right to encryption and privacy". We should be in a world where everyone building encryption technologies is building it in a fashion not just resistant to but actively hostile to any ability to control or backdoor it.
Article 12
"No one shall be subjected to arbitrary interference with his privacy, family, home or correspondence, nor to attacks upon his honour and reputation. Everyone has the right to the protection of the law against such interference or attacks."
Banning encryption constitutes "arbitrary interference with his privacy, family, home or correspondence" in my view, but it should be taken to (constitutional?) court.
I think they finally gave that one up.
You could infer from that, that the vans were for show and a shock tactic only.
It's not impossible, I'm sure.
Back in the CRT days it was reasonably possible to detect a TV program from the intermediate frequency from UHF stations, but more difficult (but not impossible, see TEMPEST) due to direct conversion by SDRs. These side channel attacks can be found here: https://en.wikipedia.org/wiki/Van_Eck_phreaking
Sensitivity of the equipment and picking up the signal from the roadside would have probably impossible in the 60s-80s. But again it's a capability you don't want your cold-war enemies (or allies) knowing about.
Also, being able to prove that the signal was the defendants, in a way that would convince a jury might have been difficult.
I'm sure some experienced radio hams/RF engineers will weigh in and correct me if I'm way off base here.
When their idiocy demands something that would cause the utter destruction of civilization as we know it (such as banning encryption) they back off. If it makes it harder for the old person to access porn, they back off. But when the consequences won’t manifest themselves before 2-3 years, they go ahead and then blame the EU or the Albanians. Let me know if they have chickenpox vaccines, Zoely (the contraceptive pill) and lactose free milk in your area. My stockpile of Calpol should be enough to survive the current shortage.
These policies will get implemented as soon as we are sick of being outraged.