North Korea, which is not famous for international expertise in many things, must, however, be a contender in the search, surveillance and bugging stakes.
I can vouch for its expertise. Within hours of arriving in the North Korean capital, Pyongyang, and being whisked out to see a display of acrobatics, a performance art curiously beloved by all Communist regimes, my belongings back at the hotel had been searched. I only know this because I happened to be carrying some packs of small cigars.
The seal on each pack was neatly slit open. Nothing was stolen from the baggage and everything, including the cigars, was carefully replaced.
Following a trip out of town there must have been another search, as I returned to find my shortwave radio unable to pick up the BBC World Service. Presumably the paranoid people who run North Korea suspected the Sony Corporation of Japan had equipped me with a radio receiver which also acted as a transmitter. Alas, this is not so, but the search for evidence clearly involved changing the radio's various settings and pushing a small switch which distorts the sound.
I conservatively estimate that I, and a colleague from New Zealand, were under surveillance for at least 95 per cent of the time we were in the Democratic People's Republic of Korea.
We had two minders and a driver (the minders also have to mind each other). Our telephones and rooms were bugged and it was clear our every move was shadowed.
The forces of coincidence are inadequate to explain how it was that one of the minders would always appear just as we were finishing a meal, or happen to be in the hotel lobby every time we attempted to leave. A journalist's visa was out of the question for visiting North Korea, so we came as tourists. It probably took the minders a day and a half to work out that we were journalists.
That was when the questions about the kind of work we did started to flow thick and fast.
It might be thought that the breaking of our cover would rapidly lead to expulsion but, strangely, this is not how things are done in North Korea. Instead of expulsion you get involved in an elaborate, sometimes uncomfortable game with your minders. You ask to see this and that and they find a thousand and one barmy excuses why this cannot be done.
For example, we were in Kaesong, near the border with South Korea. The previous day an aid official told us about visiting an orphanage in the city where the children were in pretty bleak condition.
Could we visit the orphanage? The first response was that it was difficult because it was not on the itinerary, which included visits to various historical sites. We admitted to being historically ignorant and wishing to remain so. The minders mulled this over and took us to a hotel where the head of security for the area happened to be in the lobby.
He told us the situation in Kaesong was tense and explained how difficult it would be to allow deviations from fixed itineraries. We persisted. Phone calls were made. Finally there was an answer.
We were told that, given the co-operative nature of Korean society, there were very few orphans and therefore hardly any to see.
This was a lie. How about going back to Pyongyang and visiting a creche? they said. It seemed better than viewing some bells once rung by the wicked, decadent monarchs who once ruled Korea.
The creche turned out to be a haven for the children of the party elite. It was devoid of the privations commonplace in a land ravished by famine and shortages of every kind.
Typically, the Koreans wanted to show us how well they were doing. Inadvertently they had given us a peek at the way the elite is living while the rest of the nation makes do on practically nothing.
The pride of the regime, and its unwillingness to admit the scale of the disaster it is inflicting on its people, leads it to invest in the most ludicrous schemes to erect an edifice of well-being.
That is why, for example, there are magnificent highways leading out of the capital to the southern border and up north to the centre of the country, where a massive shrine to the Great Leader, Kim Il Sung, and the Dear Leader, Kim Jong Il, pierces the tranquil countryside.
There is practically no traffic on these roads. The fuel shortage alone explains why this is so.
Yet the road going south even has a deserted highway restaurant built as a bridge spanning the road below.
Goodness only knows what kind of food could be obtained there. We made do with a cup of indifferent tea and a bottle of water.
The tricky times come when you try to take photographs. On the one occasion when we were able to spend any time alone walking the streets of the capital, we found ourselves being shadowed by two unfriendly looking men who did little to disguise their interest in our activities and seemed always to be going in the same direction as ourselves.
After this incident there was a stand-off with the minders, who demanded we hand over film shot by my colleague.
The reason given was that in taking a picture of a matron in a maternity hospital, she might have cut off the head of either the Great or Dear Leader, who were depicted in a mural in the background.
Nothing was said about the street scenes we had been photographing. I am still not quite sure how we got out of this one, although it took about 12 hours to do so.
In the end one of the minders said: "You must promise not to publish this picture."
It was the nearest they came to mentioning that we were reporters. We politely ignored the implication of this remark and no more was said.
Despite the Orwellian tinge of the country, the people, including the minders, were remarkably friendly and, in a Korean sort of way, remarkably helpful.
It is tantalising to imagine how they would fare under another kind of system.
This is the last of a three-part series