One holiday not long ago we were on Bodmin Moor, Cornwall; a dog walker, a few sheep and a man tending a crackling bonfire in the garden of the solitary house. A strange noise made us look up into the evening sky. We zoomed in with our cameras, not a UFO, but the first drone we had ever seen. Not the sort that drops bombs luckily, but what was it doing? Watching us? Is there anywhere you can go without being seen?

The next day we returned and drove up a road to investigate the tall mast on Caradon Hill we had seen from afar. Warning signs said Private road, access only. We walked the rest of the way up the grassy hill, veering away from the unmade road, past the gigantic guy ropes, steel cables holding up the metal tower. There was a complex of buildings, entry by security pass only, CCTV in operation. Obviously a secret facility, we were being filmed and I expected armed troops to emerge at any moment to take us in for interrogation. The signs were headed by the word Arqiva – a sinister secret organisation for sure.

The truth was more prosaic when I looked the place up on Wickepedia.

The Caradon Hill transmitting station is a broadcasting and telecommunications facility. Built in 1961, the station includes a 237.7 metres (780 ft) guyed steel lattice mast. The mean height for the television antennas is 603 metres (1,978 ft) above sea level. It is owned and operated by Arqiva, a British telecommunications company which provides infrastructure and broadcast transmission facilities in the United Kingdom and Ireland.

But perhaps that information was a cover up; we only escaped arrest because they had identified us as civilian ramblers.

We are all being watched, all the time. CCTV cameras we know about, on buses, station platforms, in shops. We don’t know if we are being filmed or watched live. Above us are police, military and coastguard helicopters.

It is not only people who are being watched, so is your vehicle. Drive down many main roads and your journey has been recorded by ANPR – Automatic Number Plate Recognition; if the car is stolen or of interest for any reason it will be spotted. Police cars can now carry similar equipment. Writers of thrillers or crime novels have a harder time than ever helping their characters hide or escape, though in fiction and real life criminals are often one step ahead of new technology.

But writers can find new inspiration for plot ideas.

Pity the chap whose neighbour offers to give him a lift to Heathrow Airport in his mate’s car. By the time they are driving through the tunnel they have already been spotted on the spur road. Unbeknown to the occupants of the car, the neighbour’s friend is a criminal or terrorist. When the car is stopped they will have a hard time explaining who they are, by which time the flight will have been missed.

We have all seen pleas on television for missing persons or witnesses to the movements of a murder suspect. There on the screen is a CCTV picture taken inside a bus with the exact time and date. A wife spots her husband, who never uses buses and should have been at work on the other side of the city. A good starting point for a mystery.

In Brief Encounters of the Third Kind the main characters fear they are not only being observed, but controlled. There is no rational explanation for inexplicable events and when they finally reach a glimpse of the truth it is not what they expected.